> An eephus pitch in baseball is a very high-arcing off-speed pitch. The delivery from the pitcher has very low velocity and often catches the hitter off-guard.

The pitcher essentially lobs the ball at the hitter [1]. Major league players are so focused on hitting extremely fast and/or curving pitches that they whiff or stand idle at a pitch that your ten-year-old nephew could probably clobber. It's a risky pitch, because if the batter is able to adapt, they can hit a home run. The power of the pitch is entirely that it's unexpected.

I know it's not a perfect analogy, since chess players have so much more time to react to any sub-optimal moves.

[0] https://en.wikipedia.org/wiki/Eephus_pitch [1] https://www.youtube.com/watch?v=ikLlRT2j7EQ

What you want to do is perhaps start with this random strategy, determine the realtive strength of your opponent, and only move to an exploiting strategy if they are weaker than you. If they throw Rock 40% of the time, you should throw Paper 40% of the time. If you were to enter a RPS tournament playing randomly, it is unlikely that you would reach the end. You need to exploit.

In Poker Cash Games, people just play the Nash and when opponents make flat-out mistakes they yield a little bit of profit. Do this enough with high enough stakes and it works out, even if its extremely boring. But this won't work in Poker Tournaments, where you only get payouts for top 10%, weighted heavily towards winning. So what happens in Poker is what happens in RPS - you attempt to find exploits, and your opponents attempt to find exploits in your play. In turn each of the players are attempting to move the environment of the play towards a position where they know it well and can find those mistakes.

If deviating from the Nash yields better results than the penalty of deviating because in that environment you are stronger than your opponent, you should take it. As this article points out, the same is true in Chess. And as you point out, this is also true of the Eephus pitch.

Incoming speed makes significant difference to exit velocity.

If you were going for max distance, you would want 100 mph pitches.

In home run derby, they are optimizing for ability to get a good repeatable swing with enough power to go over the fence. If they were playing in a park with like 440 ft fence, they would need faster pitches.

The distance the ball flies has a lot more to do with bat speed than ball speed (something like 5mph for 1mph, if I recall correctly).

If 'perfect' play--that we're approaching with engine analysis--results in a draw, you need to do something non-optimal and unexpected in order to get your opponent out of their engine prep and into thinking mode.

Whether it's better or worse is a different argument. Some find it a bit 'dry' in that there are often less blunders, dazzling tactics, and sacrifices because both sides now know the optimal approach. It's much more of a war of attrition in high-level, long time-control games. As an aside, that's potentially why bullet and other such chess is so popular...there isn't time to deeply analyse, so it's intuition, challenging positions, blunders, and less 'standard' play.

Not quite true; you can break ELO records by performing equally well in a larger pool of people-with-ELO-ratings.

Move A.

Move B.

From the best knowledge we have from our best engines, A is the better move (though I don't think we have formally proven such yet).

But if you play A, you are playing your opponent in a game of memorization.

If you play B, your opponent loses any memorization advantage. Thus they must play based on ability other than memorizing responses.

For a player whose memorization ability is equal or worse than their ability to play based on other ability, choosing move B is clearly the worse option. But if the player is one whose memorization is better than their other abilities at chess, then playing B means fighting them in an area they are worse at. The advantage of this can easily outweigh the disadvantage of move B compared to A in general.

Imagine a military commander choosing an engagement over terrain more familiar to their side even though it is a worse engagement if both sides had equal knowledge of the terrain, because the terrain knowledge more than compensates for the negatives.

When your opponent is the one doing the analysis. It makes perfect sense to me that anything your opponent is prepared for is less optimal than it would be otherwise.

Just that you are forced to make suboptimal moves. If you make optimal moves then your opponent will have analysed the position before and the game will end in a draw, which is a dissapointing result for whoever plays white.

Not necessarily. If black has a higher ELO rating then white is happy to draw and may aggressively seek a draw.

I think the problem is that seeking draws makes chess boring. And that it’s realistic for someone ranked well below another player to force a draw, while it’s near impossible for the lower ranked player to win outright. So you end up with a wide range of players seeking stalemates and a small minority looking for a win, but not at the expense of a potential loss.