Swerve or Stop

[mr72]

In my MSF class, they drilled into us the idea that when encountering a hazard while riding, you should quickly determine whether to swerve or to stop, but don't try to do both or you will fall or high-side. I don't disagree with this as generally good advice.

But my question is about whether we too often think "swerve" is the right idea. The study reported here seems to advocate for stopping rather than swerving because swerving may be not only difficult to do safely but may also run you into other hazards (like riding off the road). I would add that by choosing to swerve, whatever happens after the swerve happens at full speed.

I bring this up because recently my daughter was in a car wreck where someone brazenly made an illegal left turn right in front of her. She claims she was going "50 mph" but the impact was not enough to even deploy the airbag. The point here is she instinctively tried to stop and scrubbed off a whole lot of speed before hitting the other car.

Would it be wise as a motorcyclist to default in the same way to "stop, just do it real fast"? I wonder if ABS would make this a more likely best-case answer. Maybe the tendency to try to both stop and steer, and the chances of locking the brakes and losing control on a motorcycle make a big difference in margin here? Or do we think just by practicing straight line panic stops we might improve safety in wrecks? Like, rather than swerve and potentially hit another obstacle at full speed, just try to stop (nearly) all the time and when you hit the obstacle (car turning left in front of you, etc.), at least you likely will have dropped enough speed to reduce the severity of the wreck.

I'm just speculating and hoping to open a discussion.

I am thinking it might be true that if you have enough time to evaluate whether to swerve or stop, you probably have enough time to stop or nearly stop and at least reduce the wreck to one of far less risk than what you have swerving at full speed. If you don't have enough time to stop you probably don't have time to react at all.

Thoughts?

[qcbaker]

I am thinking it might be true that if you have enough time to evaluate whether to swerve or stop, you probably have enough time to stop or nearly stop and at least reduce the wreck to one of far less risk than what you have swerving at full speed. If you don't have enough time to stop you probably don't have time to react at all.

Thoughts?

Depends on the environment obviously, but more or less I agree with what you said here. I think that most people (myself included, probably) are not skilled enough motorcyclists to make a snap judgement to swerve and do so safely at a high speed. If there's suddenly an obstacle in front of me, my reaction is almost always going to be to get on the brakes. Most of the time, swerving isnt really an option as it would either put me into the marbles or into a guardrail, or into oncoming traffic. I don't really ride anywhere where swerving seems safer than stopping. If I was on a 3-4 lane highway with very little traffic, maybe I'd feel differently, but most of my riding is done in the woods where I can't usually see what's around the next corner very well.

[cbrfxr67]

I was coming in hot to make a green light last week.  It was a left turn and I was on gsxr.  Things going good, until I saw a huge splash of OIL right in my trajectory. 

It was cold and I was certain my tires were going to slip on it.  I hit the brakes.  Yes, I was going way too fast but dry and clear, I would have been ok. 

Locked up the rear for a second and looked like a doof  but avoided that oil slick and felt it was better to brake.  I guess it depends on the circumstances mr72.

[Kilted1]

Sometimes stopping is the right thing to do.  Sometimes swerving is the right thing to do.  Sometimes accelerating is the right thing to do.  It just depends on the situation.

In the classroom we can develop all sorts of decision trees and determine the best course of action in a given instance.  On the road in the real world we have to rely on our experience, training, and instinct to react to whatever happens.  Ideally we act in advance to a developing situation, perhaps as subtly as changing position in the lane, early enough to avoid the need for emergency reaction.   The vast majority of the time it all works out and we move on with barely a recognition that something might have happened.

Keep your eyes open and your head on a swivel.  In driver training most of us learned to "assume they don't see you".  That's fine when you're sitting in a two ton steel safety cage with air bags.  On two wheels it's safer to assume they see you, and want to kill you.

[Watcher]

An important thing to realize is that the braking and the swerving are more a means to an escape rather than the escape itself.

The "brake or swerve decision" isn't really taught in MSF anymore, at least not directly.  It used to be the same exercise challenged the rider and/or gave them a choice to brake or swerve either left or right to overcome the same "obstacle".
Now it's divided into two completely seperate exercises, and done so to focus on the building of the technique, not the building of the decision.  Ultimately we're lazy and will take the easiest path, thus if I'm best at right hand swerves I'll naturally focus on that, but what happens when that path isn't available?
So instead we teach the techniques on the bike, and teach the theory off the bike.


To me, it's not enough to "brake to avoid hitting the hazard" or "swerve around the hazard".
It can definitely be one or the other, and it can definitely  be both, it's just not the best practice to do them simultaneously.  But ultimately we're trying to use an escape path here, and that should be the focus.


Let me share the story of my first real close call:

I'm on a frontage road approaching a fork, keeping on the path "straight" will follow the road, the fork branches off to the left and leads to some businesses.  A car is positioned in the center of the fork, left signal on, stopped and waiting for oncoming traffic to clear.  I keep the throttle open, and proceed straight ahead at ~40mph, planning to pass the car and continue.

Within maybe 25-30 yards of the car, suddenly the driver changes her mind and without even cancelling the signal veers into the lane to continue straight.
I apply the brakes, and instinctively hit the horn, and on hearing this the driver freezes and STOPS IN THE LANE!
I don't have enough stopping distance, so I release the brakes and instead swerve onto the right shoulder, then reapply the brakes coming to a stop roughly even with the rear passenger door.
The driver turns her head to the right, makes eye contact with me, and without a word or gesture looks back straight ahead and drives away.

I get off the bike for a minute to keep my heart from exploding out my chest.  Driver behind me (stopped) gestures to me asking if I'm ok, I thumbs up and hop back on.
Go on about my ride...


If I had made a "braking decision" I'd have rear ended that car, no question.
If I had made a "swerve decision" I'd have probably lost control on the gravelly shoulder and dumped it.
But because braking and swerving were both means to a safe escape, which was essentially slow, move over, then stop, I can share a story that has a frustrating but happy ending for all parties involved.


Escape paths are everything, and having multiple at all times is the key to being a safe rider.  Limiting choices to "brake" or "swerve" is too narrow focused.

[cbrfxr67]

Thanks for sharing watcher,...!

I hope other people will share.  Sometimes I watch yt crash videos and go over and over what I'd do to escape.

[mr72]

I have done exactly the maneuver Watcher describes at least once or twice in Austin traffic when cars are backed up in the lane to the left, I'm traveling in the right hand lane, and a car in the left lane pulls in front of me. Fairly common to turn slightly to avoid hitting the car and then brake hard, landing in the shoulder. This is a good example of a situation where decades of driving a car in the same kind of traffic informs one's reflexive reactions. I don't think this scenario is what I was talking about though. What I meant was, when training yourself to do emergency accident avoidance, should "stop" be the main/primary/only thing we train? Does "swerve" option introduce confusion that might lead to an attempt to do both which would wind up with a worst case scenario? And is there really a range of situations wherein swerving is the better option? Is this close to 50%?

Maybe I should reframe my hypothesis:

- if you have time to think about it, you probably have time to stop
- if you don't have time to think about it, you're better off braking than swerving since it will reduce the speed of impact in any case
therefore
- it is [nearly] always preferable to attempt to stop.

I guess when thinking about this hypothetically and in the ~10K of riding I have done in the past two years and change I can't think of any situation where "swerve" is the better choice except those where it's not truly an emergency/panic type situation. If I am training my reflexes, I think it's best to just learn to stop hard safely as a default response.

[Kilted1]

If you're talking about self-training in a parking lot, certainly practice both.  I would say about equally.  I won't bore you with my logic and would certainly defer to others who are professional trainers but I think it's important to practice both skills.

[Watcher]

- if you have time to think about it, you probably have time to stop
- if you don't have time to think about it, you're better off braking than swerving since it will reduce the speed of impact in any case
therefore
- it is [nearly] always preferable to attempt to stop.

If you have time to think about it, I think you have ample time to avoid the hazard regardless of your choice.

Not necessarily, as an alternate path could be totally open and clear, such as another lane of traffic, or a different position within your own lane.  This may depend on the magnitude of the hazard.  For example, I see no reason to stop because of debris in the road, but a swerve may be necessary to avoid a pothole or someone's lost muffler.
There's also the scenario of, perhaps, a car coming out of a hidden driveway into your path of travel.  If that happens 20 feet from you is that ample stopping distance?  Probably not.  But swerving has the nearly instantaneous effect of removing you from a collision path.  Braking doesn't change your path.
You might argue that you should slow, then swerve, but there's also the risk that, depending on how large/close the object we need to go around is, you shoot yourself in the foot and effectively limit your space cushion.  Regardless of braking, you still are travelling towards the hazard, not away from it, which is what swerving does for you.

I disagree.  I think it's 100% situational, and not just dependant on the hazard and road conditions, but in the rider's confidence and personal skill.
Truthfully, if there weren't things like curbs and other cars and such that limit options to the sides, I think swerving would be a vastly superior technique to avoiding collisions.
But since we can't always redirect our path of travel, braking is an essential option.
The braking favor I think is a driving holdover.  I can't think of a lot of situations where swerving is even possible in a car, and cars have a major mechanical advantage over bikes when stopping.
A bikes mechanical advantage, I guess, is in it's small size, opening many avenues of travel to avoid collisions.

[cbrfxr67]

'yea, then i was just riding along and,....blaaaarg!'

[mr72]

Watcher I think you are describing non-emergency maneuvers, wherein there is time to make a choice between swerving or stopping.

I now regret bringing this up. OK, I get it. We all think we have instant reaction time and can make the right choice between two things. My own reality says that's simply not true. There are things that happen too quickly for us to make a decision on a response, and we react by reflex.

It's not reasonable that a muffler or pot hole is going to appear in our path without sufficient time for us to make a decision whether to swerve or stop. That car that backs out in front of you, well if it's really 20 ft in front of you when they pull out then you will have less than 1/4 of a second at 60mph before you hit the car. That's not enough time to assess and decide to swerve, or really to swerve even if there was no reaction time. So I suggest you will do better to just ALWAYS brake in that condition so you may be only going 30mph when you hit the car's fender rather than hitting the car's rear fender at 60mph because you decided to swerve, assuming you can actually decide to swerve and make a meaningful direction change before you hit the car.

I was in two car wrecks where precisely that kind of thing happened. One at about 45mph and another at about 50mph. In both cases a car emerged from behind an obstacle (one was a semi truck parked in the shoulder, another was a long line of stopped traffic to my left) and entered my lane of travel without nearly enough time for me to even know what had happened. In both cases after the wreck I was just mystified as to what had just occurred. I T-boned both cars at full speed without enough time to do anything, but skid marks in both cases indicate that I reflexively got on the brake even though I have no conscious memory of ever even knowing I was about to be in a wreck. Now who knows how fast I was actually going when I hit those cars but both cases totaled my cars, one had no airbag and I broke ribs and knocked other ribs loose from my sternum from the seat belt, the other had airbag and I rammed my knees into the dash so hard I had to go the hospital and I couldn't walk for about a week. Those were really hard hits folks, and that's AFTER braking in a 4-wheel vehicle, one of which was a Miata with huge tires and sub-100ft 60-0 stopping distance.

That's my point here. The reflexive action we train ourselves to do, I think, should be to brake, rather than to assess or to swerve.

All of these situations that are brought up are of the "have time to decide", and I stand corrected: if you have time to decide there may certainly be times when braking is the wrong answer. Sometimes you have so much time to decide it doesn't even register that you were deciding what to do. But in the "only have time to reflexively do something", I think reflexively braking in a straight line is safer on average.

[Watcher]

Watcher I think you are describing non-emergency maneuvers, wherein there is time to make a choice between swerving or stopping.

All of these situations that are brought up are of the "have time to decide", and I stand corrected: if you have time to decide there may certainly be times when braking is the wrong answer. Sometimes you have so much time to decide it doesn't even register that you were deciding what to do. But in the "only have time to reflexively do something", I think reflexively braking in a straight line is safer on average.

Negative, I think you're misunderstanding my point.

To clarify, lets change gears here.

Imagine, you are riding down a road and you close your eyes.  You keep them closed for, say 10 seconds.  You open your eyes and suddenly there's a car pulling out of a hidden drive 20 feet in front of you and you're traveling 60mph.  I think you WILL NOT have any time to decide on any course of action besides reflexive braking, as swerving requires a path that was mentally laid out ahead of time.  Braking alone may not be sufficient, swerving alone may not be sufficient or may put you in another dangerous position, and braking while swerving is a good way to just crash.  So the result is of course going to be rear ending the car, best to rear end it as slow as possible, you're correct.

Lets twist that, the rider spaces out for a stretch of road and a car pulls out in front of them, but this time they have a large enough time and space cushion to make a decision on what to do.  You may be correct that braking is the preferred course, because once again I think "If you have time to think you'll have time to avoid it regardless" but, once again, changing course requires some mapping.  So the easier solution is to slow and possibly stop.


But going back to the escape path thing.  Escape paths aren't a "think of when the time comes" sort of thing.  Escape paths are a constant creation from the rider.  All that is left when a hazard reveals itself is to decide, the "brake or swerve decision" then is a much more reflexive thing than thinking of how to avoid said obstacle.

So lets say then I'm riding down that road with sight lines blocked to the right, I'm already setting myself up to the left so I can see better and I'm laying down escape paths to my left, as well as considering slowing or stopping.  When the car comes out of that blind driveway, I don't have to think of what to do, there isn't enough time.  But there IS enough time to decide which escape path I'm taking.  In this case it's more than likely to be a swerve.


The pothole/muffler example.  Maybe not super-emergency, but if you're following a car a little too closely a pothole or something might suddenly reveal itself.  Once again there's that brake or swerve decision.  I don't want to leave even something relatively minor like that to pure reflex, and if I'm far enough behind that car that anything that appears I have ample time to think about then it's a non-issue.  But even something as minor as a potential pothole has me thinking of escape paths in real time, and all I have to do when a threat comes out is decide.



At 1:55 a clip of me riding along and I have a car come into my lane.  In the position I was my escape paths were swerve or stop.  When the threat was recognized I simply made a decision.  Swerve left.  Could I have braked?  Sure, but the swerve was both safe, smooth, and quick, and as a bonus had the lowest impact on surrounding traffic.

This is what I'm referring to.  Once again, I think the escape path is the end all when it comes to crash avoidance.  It's not always going to be brakes, it's not always going to be swerve, but if you leave it up to reflexes you're putting yourself at a disadvantage because I think most people go for brakes when brakes isn't always the best choice.  In that clip I am cut off shortly after changing lanes in front of a car, what are the chances my heavy braking would have resulted in a rear-end collision?

So I think it's poor to default to "braking is best if you are in a bind," that's a potentially dangerous mode of thinking.
I think this is someone who is unprepared mentally for the task of riding.  Be it a momentary lapse in concentration or just poor judgement on the whole, if you aren't exploring all options equally then you are putting yourself at higher risk.

[Kilted1]

I now regret bringing this up.

I for one am glad you brought it up and am enjoying the discussion! 

If you want to practice emergency stops, that's great.  I don't think anyone can say you're wrong and I think everyone should do so.  I just don't think it should be the only trick in your bag.  Emergency stops are part of the MSF curriculum for a good reason, but they aren't the entirety of the MSF curriculum, also for a good reason.

[mr72]

I now regret bringing this up.

I for one am glad you brought it up and am enjoying the discussion! 

I think the point that is getting vociferously buried on this topic, which clearly I am not able to make well, is this:

THERE ARE CIRCUMSTANCES WHERE YOU WILL ABSOLUTELY ONLY HAVE TIME TO RESPOND BY REFLEX

That reflex will be a result of whatever you have trained yourself to do. And if we train ourselves to "decide" between stopping and swerving, then that's the worst case. So I suggest we are better off training ourselves to stop, which will have better outcome in most cases than trying to swerve.

Watcher [totally unintentionally] seems to be suggesting that you can somehow eliminate from all possible scenarios those where you do not have time to make a choice to react and only wind up responding by reflex. Objectively, this is just not true.

But still I think the default choice should likely be to stop, unless it's a clear case where swerving is the better option. I think though that you waste critical response time by trying to evaluate, and that response time would be better spent by adding it to braking time and further reducing speed prior to impact.

Thankfully I have no objective experience on a motorcycle, since I've never had a wreck. But I've certainly stopped/braked and/or changed direction to avoid accidents probably multiple times every time I ride, so it's not like I'm unfamiliar with accident avoidance.

[qcbaker]

Watcher [totally unintentionally] seems to be suggesting that you can somehow eliminate from all possible scenarios those where you do not have time to make a choice to react and only wind up responding by reflex. Objectively, this is just not true.

I don't think that's really what Watcher was suggesting (and he can certainly chime in for himself as well, not trying to speak for him). To me, it read more like he was saying that the time needed to make a snap judgement about whether to swerve or stop is lessened if you are always searching for escape routes. If you already know what your possible escape routes are, you don't need to spend time trying to figure out where to swerve, you already know that. So, your decision only comes down to whether to swerve or stop (or some combination thereof), which is much more of a reflex-based decision than a logic-based one. So, it seems to me that you both essentially agree that there exist certain situations in motorcycling that require you to make a reflexive decision rather than spend time thinking about it. Its just that the thing you say takes the time to think about (calculating an escape route) is something that you should always be considering while riding, not just in the moment of crisis, so to speak.

In other words, if you are constantly considering your plans to avoid an incident in advance, your reflexive decision is just deciding which plan to use, not having to come up with that plan on the spot.

My take on it is that you should try to be the kind of rider who plans ahead and always has escape routes planned, so when the time comes to avoid an accident, you already have contingency plans and all you need to do is choose the best one for the situation at hand. But, you can't plan for every eventuality. So, its always possible that you have a "shaZam! has hit the fan in a way I had not expected and I do not have time to make another plan" type of situation, which I think is what you're saying (correct me if I'm misinterpreting). And in that situation, I'd probably get on the brakes hard before doing anything else, even if it isn't the ideal maneuver.

[qcbaker]

Accidental double post

[mr72]

To me, it read more like he was saying that the time needed to make a snap judgement about whether to swerve or stop is lessened if you are always searching for escape routes. <snip>

Yes, and I was assuming that as a normal baseline, and those events where you can make the "snap" decision are not those which qualify to e as an emergency.

In other words, if you are constantly considering your plans to avoid an incident in advance, your reflexive decision is just deciding which plan to use, not having to come up with that plan on the spot.

Yeah, I agree that's the same interpretation I have to Watcher's comments I still say if your reflex is to "decide", that is [potentially] inferior to your reflex to be "brake", because there remains a higher risk of poor outcome if swerving in such a situation (not all the time!!), so on the whole motorcyclists will have average better outcomes if they simply brake in these situations rather than taking the time to decide and then potentially choosing a more risky option.

My take on it is that you should try to be the kind of rider who plans ahead and always has escape routes planned, ...

Yes, I assume that's the baseline for anyone in this forum, particularly because we all seem to be interested in our own safety.

...in that situation, I'd probably get on the brakes hard before doing anything else, even if it isn't the ideal maneuver.

I think it's the lower-risk maneuver on average, even if on a case by case basis it might be the lesser choice.

Just making up numbers here, since there's no way to quantify this, but let's imagine that one time out of five, swerving could result in avoiding impact altogether, so it would be preferred. The other 4/5 of the time, braking is preferred, even if you are going to crash, because at least you crash at a lower speed.

However, to take advantage of the 1/5 of the time you swerve, then you must do two things: 1) reduce your reaction time by some quotient in order to make a decision whether to swerve or stop; 2) be well-practiced in swerving enough to successfully make the maneuver. Now let's imagine that when swerving, if you make a mistake or another unexpected obstacle comes up, then you wind up in at least as bad of a wreck as you would have if you would have braked. So perhaps this happens 1/5 if the time too ? Just by probability, I would say that to gain back the reaction time you would have otherwise lose, you will be better off just braking in all cases where you do not have sufficient time to have already planned an escape route because in 4/5 of these cases, you will improve your outcome by braking more/longer, at the cost of the 1/5 of the cases where a better outcome would be achieved by swerving. And you avoid any risk of subsequent crash resulting from poorly executed swerve, lack of practice, or other impediment introduced in real time after you decide to swerve.

I agree that for most of us, brake hard is going to be the default. I am concerned that the MSF is trying to break us of that default position to our detriment, by teaching the "stop or swerve". Watcher is up on this and says they don't teach that anymore but they did for me about 2.5 years ago including a drill. This sort of passively teaches us that making a decision is important as a first step, and I think maybe we should be teaching that just stopping is the best reflex in 90% of the cases, such that there is marginal value for a beginning or inexperienced rider to developing a habit of making a stop/swerve choice.

[Watcher]

Thanks QC, my thoughts exactly.  I want to specify that the "brake or swerve decision" should be interpreted as "deciding on the braking path" or "deciding on the swerving path", not deciding to make a plan that either involves braking or swerving, which seems to be how most people interpret it.
It's more effective as a broader plan than a snap judgement.


I'm also trying to make the argument against "braking is better than swerving" in a purely muscle-memory reflexive "ShaZam! hits the shaFan!" type of scenario.

I think the average rider has a natural preference to stop as it's a simpler action (no need to pick a course, just apply the controls), and I won't disagree that if you end up swerving directly into something you'll hit that something at full force, but in a snap decision I believe you are more likely to avoid the collision by swerving, where as more likely to be involved in the collision (all be it at a lower speed) when only braking, since altering course puts you out of immediate harm's way.  Furthermore, if there is another collision trap as a result of your swerve you may have more time to deal with this one now that the first one has been successfully avoided.


The article points to swerving as a poor choice as the bike may leave the roadway especially if the rider has poor skill.  However, it does not go on to confirm if the bike leaving the roadway resulted in a crash.  In my cited personal example, I left the roadway and didn't crash.  However, continuing to brake would have resulted in me crashing into a car.
I would absolutely prefer leaving the roadway to colliding with a vehicle or other object, even though leaving the roadway is inherently dangerous.

They do highlight increased danger with poor skills.  Riders should absolutely be practicing swerving.  It's easy to do with relatively low risk on a daily basis on public roads at roadway speeds.
Traffic allowing, just swerve around manhole covers and painted lines and stuff.
Emergency braking essentially requires you to practice in a controlled environment, making it sometimes difficult to properly develop.  Swerving is a lot less demanding, and once proficient I think can be a more favorable action than braking.


@mr72

I really dislike your 4/5 braking is better argument if for nother reason than the statement "braking is preferred, even if you are going to crash, because at least you crash at lower speed."
To me, any crash is a failure.  It's the same reason I really can't stand the "I had to lay it down to avoid a crash" BS.  You crashed trying to avoid a crash.  Sorry not sorry, but you either made a bad decision or you are a bad rider.
Nothing against them personally, but it's a valid conclusion.  Almost no crashes are unavoidable, people who do crash either lack the skill, lack the judgement, or made a poor choice.

If you are fine with the decision that leads to a low speed collision, that's something you can live with on your own.  To me that's unacceptable.
It's hard to say with certainty since this is all hypothetical and speculative, but if you  say to me "in this situation I only had time to brake, but I still hit the car" I'm going to respond with "that's bull crap, there was somewhere you could have swerved to, you just failed to make the correct decision."

I'm almost the complete opposite, I think in the majority of situations a swerve is preferable to a stop.  To me stopping is a last ditch nowhere to go action.

Once again, I think it's more naturally reflexive, but I don't think it's the better choice.

[qcbaker]

Yes, and I was assuming that as a normal baseline, and those events where you can make the "snap" decision are not those which qualify to e as an emergency.

I guess I just disagree with you on that then. I think that those events still qualify as an emergency. For example, if I'm riding behind a car (assume a reasonable following distance and that I'm not tailgating) and they slam on their brakes because a deer jumped over the guard rail and they just hit it, I have a decision to make about how I'm going to react. My reflexes in most situations are going to be to brake, so I guess I'm with you that braking is my default. But, reflexive or not, its still a decision I'm making. My reflexive reaction could be different depending on the variables of the situation (speed at time of crisis, following distance, road conditions, traffic, etc). And to me, it qualifies as an emergency because the situation puts me in mortal danger.

Yeah, I agree that's the same interpretation I have to Watcher's comments I still say if your reflex is to "decide", that is [potentially] inferior to your reflex to be "brake", because there remains a higher risk of poor outcome if swerving in such a situation (not all the time!!), so on the whole motorcyclists will have average better outcomes if they simply brake in these situations rather than taking the time to decide and then potentially choosing a more risky option.

I guess my position is just that just because most of the time my reflex is going to be to brake doesn't mean that I'm not still making a decision. Maybe it's only a semi-conscious decision, but a decision nonetheless. If the situation is different, and I have already planned an escape route, my reflex at the time might be to swerve. Its very situation dependent.

Yes, I assume that's the baseline for anyone in this forum, particularly because we all seem to be interested in our own safety.

No argument here.

I think it's the lower-risk maneuver on average, even if on a case by case basis it might be the lesser choice.

Just making up numbers here, since there's no way to quantify this, but let's imagine that one time out of five, swerving could result in avoiding impact altogether, so it would be preferred. The other 4/5 of the time, braking is preferred, even if you are going to crash, because at least you crash at a lower speed.

I think that you're probably right about braking being the lower-risk choice on average. So if you're gonna roll the dice, better to bet on that than the other way around. And I'd probably agree with you that if I went through all of the if...elseif...elseif...etc statements in my head, the final "else" would just be "brake hard and hope for the best" because of that.

However, to take advantage of the 1/5 of the time you swerve, then you must do two things: 1) reduce your reaction time by some quotient in order to make a decision whether to swerve or stop; 2) be well-practiced in swerving enough to successfully make the maneuver. Now let's imagine that when swerving, if you make a mistake or another unexpected obstacle comes up, then you wind up in at least as bad of a wreck as you would have if you would have braked. So perhaps this happens 1/5 if the time too ? Just by probability, I would say that to gain back the reaction time you would have otherwise lose, you will be better off just braking in all cases where you do not have sufficient time to have already planned an escape route because in 4/5 of these cases, you will improve your outcome by braking more/longer, at the cost of the 1/5 of the cases where a better outcome would be achieved by swerving. And you avoid any risk of subsequent crash resulting from poorly executed swerve, lack of practice, or other impediment introduced in real time after you decide to swerve.

I don't necessarily disagree with your logic here, the only thing I would say is that I would just advocate for the two points you mentioned: reducing your reaction time and be well-practiced in both swerving and stopping. And both of those things can be done with practice, which riders should be doing regularly. You (and I, and everyone reading this) should go to a parking lot every so often and practice emergency stops, practice swerving, maybe have someone with you to give you a signal about when to do something so you can train your reaction time, that kind of thing.

The more you hone your reflexes and situational awareness, the less you have to rely on dice rolls in high-risk situations.

I agree that for most of us, brake hard is going to be the default. I am concerned that the MSF is trying to break us of that default position to our detriment, by teaching the "stop or swerve". Watcher is up on this and says they don't teach that anymore but they did for me about 2.5 years ago including a drill. This sort of passively teaches us that making a decision is important as a first step, and I think maybe we should be teaching that just stopping is the best reflex in 90% of the cases, such that there is marginal value for a beginning or inexperienced rider to developing a habit of making a stop/swerve choice.

I did my course much more recently (technically I did Total Control instead of the MSF course though, so grain of salt and all that) and they didn't really "drill" us about choosing swerving or stopping, they only drilled us on the individual techniques. Then, in class, we talked about situational awareness and when to apply each technique based on situational variables.

[mr72]

Almost no crashes are unavoidable,

This is demonstrably not true. I guess it depends on the quantity which is "almost no" in that statement.

Assume we successfully avoid all crashes that are avoidable. What remains are the unavoidable crashes or at least unavoidable probability of a crash. Sometimes you have to plan for the best of bad outcomes.

BTW in about half a million miles of driving over 30 years I have had 7 car wrecks and only one could have been avoided. If I had been on a motorcycle in those crashes, only one of the unavoidable car crashes would have been possible to avoid on a motorcycle unless you could see the future.