the dorbel daily

Monday, 26 April 2010

Crawford Rule Change?

Anybody who plays tournament backgammon will have encountered the Crawford Rule. It stipulates that when one player reaches a score one point from victory, the doubling cube may not be used for the next game. If the trailer wins the Crawford game, he can and should double the next game at the first legal opportunity. I have often wondered though, why only one game? If you have reached 10-2 in an 11pt match, but then lose the Crawford game, your opponent will be doubling every game and will effectively be handed four points for nothing! In practice, he doesnt trail 10-3, he trails 10-7 in a match where the cube doesnt count. How can that be fair?
I can see that it is fair that he benefits from winning gammons, that requires skill, but there's no skill to just turning the cube straight away. Changing the rule, so that no doubling was permitted for the rest of the match would be fairer and would incidentally, increase the wins for the more skilful player, a desirable outcome in itself. I have to say that I have yet to meet anybody who agrees with me here!
Why have a Crawford rule at all? Without it, certain cube actions at the end of the match become nonsensical. At the 2-away, 3-away score for example, if the trailer doubles, the leader can take anything at all in a gammon free position! If he passes, he is 50/50 in the match, if he takes and loses he trails 2-away, 1-away, doubles the next game immediately and is still almost 50/50, except for the leader's free drop.

For our newbies it might be good to explain the "Free Drop" and it's close relation, the "Mandatory Take". The Free Drop occurs post Crawford, when the trailer needs an even number of points for victory and doubles. The leader can drop without losing any equity. Having the free drop is worth a little bit, perhaps as much as 1.5% in match equity. When the trailer needs an odd number of points, the leader always has a take, even if he is well behind in the game. This is known as the Mandatory Take. The exception to this comes when the trailer stands to win more gammons than he loses games, but these positions are rare. However a clever trailer may sometimes delay his cube until there is a substantial gammon threat in the hope of getting a wrong pass! You have to be careful though; reaching a position where the leader really should pass would be a disaster!
Another rule change that would slightly reduce the luck factor, would be for players to alternate getting the first roll of the game. Roll dice for it on the first game, then alternate after that.
Any thoughts on these ideas? Any rule changes you would like to see? Use the comment feature and let's get interactive!


ah_clem said...

You can add me to the list of people who disagree with your proposed changes to the Crawford rule. Usually when there's a really lopsided score post-Crawford, it was arrived at by a combination of gammons and cubes. For instance, suppose in a match to nine you turned the cube, then I got lucky and recubed followed by a gammon. Thus we arrive at a score of 8-0 in one game. Is it fair to make you win nine cubeless games in a row to offset my one victory? I don't think so, and the current Crawford rule seems to do a good job at balancing things out.

I do have some sympathy with your opening roll proposal. What I think would be best is for the players to roll for the first game as they do now, but then the loser of each game gets to roll first. Sort of like in curling, where the team that's scored upon gets the hammer, only it wouldn't be as big of an advantage.

But, as the game has been like this for a long time, I doubt we'd make much headway in changing the opening procedure. For one thing, we'd need to tweak the match equity tables - one-away one-away wouldn't be 50% any more.

Unknown said...

Rules are Rules and as a general principle I am against changing them.
Grand Prix racing and cricket seem to change the rules every season..all with the best intention but resulting in the majority of the followers and participants being confused.

dorbel said...

Thank you Clem, of course the leader may have got to 8-0 with excellent play over several games, or even played brilliantly to win a redoubled gammon, or even been astoundingly lucky. I still don't see why the trailer should be handed four points as a bonus for winning the Crawford game!
Thank you Ash. There weren't any wheels on carts until somebody thought of them, nor any crawford rule until 1980(?), nor even any cube until about 1930. We shouldn't mind change if it is for the better.

ah_clem said...

I still don't see why the trailer should be handed four points as a bonus for winning the Crawford game!

One reason is that it makes the match more interesting. Even at eight-zip the trailer has a chance to come back to win. And if the leader is really the better player, he should be able to win one out of four one-pointers, or stated another way, the player who can win four one-pointers in a row deserves to win.

Also, think about what it would do to our doubling decisions if your rule was in place. We'd be much more reluctant to take cubes that could lead to Crawford, which probably leads to less exciting play.

dorbel said...

I can't see why giving the trailer 4 points "makes the match more interesting"!
Yes cube decisions would of course be different, but again, I can't see why it would lead to "less exciting play".

Anonymous said...

Speaking as a player who has won my country National Backgammon championship (using the normal crawford rule) - I think a fairer test of skill would be to give each player say 7 (you can increase it at various stages of the tournament). Have No crawford rule, just the rule that you cannot win more chips than you own. Like poker, it would be easier for new players and spectators. Then let them play until one of the players has all the chips or a time limit has expired (if each move is time limited). We are loosing the popularity contest to poker (an inferior game).

dorbel said...

Yes, but that would be a different event. I am not sure that it would be any more exciting for spectators or players anyway.