Score is 1-0 white to 5 points. White owns cube, red to play 33.



I quickly switched points and re-slotted with 4/1*(2) 10/4, but the right move was the "obvious" play, just hitting loose on the ace with 10/1* 18/15.

Since the goal here is to close the board ASAP to lock in the gammon, switching points seemed to make sense as, if white hit my blot from the bar, reinforcements (i.e. my back 2 checkers) would be coser to the 4 pt than the ace pt. However, this is obviously wrong.

I can see that switching may cost me some wins as it sacrifices the 5pt prime, but how does keeping the 5pt prime win me more gammons? Aren't I a big underdog to gammon as soon as he anchors, regardless of which point it's on?

In general, when is point switching better than keeping the prime intact?

First point: while the best play is 10/1* 18/15, the best switching play is 4/1*(2) 18/15 10/7. You almost never want to slot a point when your opponent has two men on the bar.

You've got a couple of goals here. One is to win the gammon. The other is just to win the game when White gets lucky and enters his men quickly. Keeping a 5-prime doesn't help you win a gammon; it does help you win the game after he gets lucky and anchors. If you switch and he gets both men in, you're in big trouble. If you keep the prime and he enters, he has much more work to do to win.

In general, you switch when it's the only way to get your opponent on the bar, or when switching brings lots of builders to bear on the open point. Not the case here.

Thanks Bill! Great explanation.

Also, thanks for the point about not wanting to slot when there are 2 of the opponent's men on the bar-- definitely something to keep in mind for future blitzes.

What would be an exception to this? Perhaps an early game blitz, where neither side has much of a board?

When he has 2+ men on the bar, his anchoring chances are very slim, so why take the risk of being hit? It's better to wait for him to enter one of his checker, and then you want to hit (if you're in blitz mode) to prevent him from anchoring.

I think the open blot on 24 is the reason the bot says slotting play is better. I haven't checked but if that blot wasn't there I think the switch play would come up first.