Why is 5 off 1 off an error -0.020?

XG states that 5 off 5/4* is better and I do not know why. With my move he has eleven shots at getting a one and with XG's he still eleven shots at getting a four, but with an extra checker on the board!

Since posting this query I had the same position on Galaxy and I played the move that XG suggested. Now Galaxy says that I have made an error and should have played 5 off 1 off!

My guess is that since you have no checkers off yet, he still has a chance of catching up and winning with a few high doubles. Hitting puts them behind a bit more and has the potential for them to dance.

If they do hit you next turn, that's such a big loss in equity for you, the advantage of that extra checker is relatively meaningless (and they have a clear double/pass). You also leave a blot on the 1-point that black can hit on the small chance you're able to hit them back from the bar later on. Negating a lot of the advantage the extra checker off would give you.

Take another look at the two positions you posted, they are clearly not the same. Blue's home board is still open and you already have 4 checkers off. If blue hits you there, you not only can get back in, you're still in the lead significantly. You also have a spare checker on your one point, making it safer if you can hit back later on.

Many thanks for the feedback and the explanation on the difference between the two positions.