To hit or not to hit?

Recently I came across this position when playing Gnu Backgammon:

 

 

White to play 65

 

I thought that the big decision is: hit with 13/2* or play it safe with 13/8, 9/3. I hit on the 2, reasoning that I'm only slightly ahead in the race (4 points before the move), I have the stronger board, and gnubg has two blots in his home board, so if it manages to re-enter and hit me it should not be able to consolidate its board. I concluded that I'm well ahead if I hit.

On the other hand, if I play it safe I have no blot, but I risk that after 62, 55, 54, 53, 52, 44 gnubg gets out. That's 10 rolls that make the game even.

So I played the big blunder 13/2* (-0.21 equity compared to 13/8, 9/3, according to XG2's rollout).

Here's the dice distribution of gnubg rolls after my two moves:

 

Rolls after the best move, 13/8 9/3. Only 55 is dangerous (bringing gnubg's blot to safety)

 

 

Rolls after my move, 13/2. If gnubg hits me with a 2, XG considers me no longer a favorite.

Seems I overestimated the danger of gnubg escaping when I play safe - only a 55 diminishes my significant lead. I also underestimated my winning chances. I was expecting a small lead like 0.2, not the 0.8 XG assesses. 

My hitting move makes gnubg a favorite if it hits. That's also something I didn't expect. But if you actually look at the positions after every move 2+x, it shows that gnubg can always cover one of the blots and make a three-point board itself, giving us an almost symmetrical position (and costing me 23 pips in the race, obviously).

The basic lesson I learned: with a big roll like 65, don't consider the pipcount before but after the move. I was not 4 pips ahead but 15, which is quite a lead and which suggested a conservative play.

Why should I not drop here?

In my last match against XG2, I thought I was clever and XG2 refused to believe that I am. I'm still stunned why my thinking is wrong.

Match to 7, I'm leading 6:4, Crawford game. I roll an initial 62 which I consider poor. XG2 actually agrees, rates my position after that 62 as -0.3. 

XG2 does the automatic double, and I think "well I have three attempts to win that one point, I'm sure I get a better first roll than 62 in one of these two. I drop.

XG2 then tells me I've wasted 0.7 equity and played this like a total beginner. XG2 can be cruel in its assessment of us humans.

The match continued with a next game that I correctly dropped after two unlucky rolls, and a final game in which my first roll was a beautiful 42, so I could start with 8/4 6/4 which is a much better start than the above...

Update: it turns out (thanks to David Startin on Twitter) that my reasoning was, well, flawed. Yes, I only need to win one more game, but a game is more than a good start. So by passing I gave away a match where XG needed to win two games (the first to 6-6, then a final one), the first of which had a mediocre start for me, for a match where I got a better start but XG needed to win only one game, which clearly is a big blunder.

My greatest misses, part 1: a subtle detail on bearing off

Okay, I'm only an advanced level backgammon player dreaming of playing on expert level some day, but maybe my worst blunders can be instructive to other non-pros. 

Here's one you might enjoy. It might be trivial for you, and I'm embarassed that I missed it. I learned - situations that look like "there's only one move so don't even start thinking" are still worth thinking.

 

 

Here I didn't think. It was clear, there is only one checker that can move the 6, so I moved 8-2. Then I needed to move the 4, so I moved 3-off. XG tells me this is a horrible blunder worth half a point (0.44 to be precise). 

The right move is to move the 4 first - 8-4, and then bear off the 6 with 4-off, leaving no blot.

Why is this the best move?

 Have a look at this simple position:

Without much thinking, I played 24/23, 13/11 here. This adds another builder, splits my back men, looks like the straightforward choice.

However, XG stubbornly recommends 24/21 as the best move. Mine is fine, too (-0.05 worse). But still, why should I not put a builder on 11?

The answer is probably that the builder doesn't help much - I already have the 5 point, 11 is too far away from the four point, and as my 8 point is stripped and my opponent has a stone on 2, building the 7 point in the next move with e.g. 11/7, 8/7 is not an option. Also I underestimated that black has some really great rolls like 55 or 44. XG (on Roller++) also says that 13/10 would be slightly better than my move, because then the builder on 10 actually has something to build - the 4 point.

On the other side, black has made the 18 point, threatens to make the 20 point, so helping one checker to escape is reasonable.

Sometimes the straightforward move is not straightforward.

Do you agree? Any thoughts are appreciated.