At first i thought hitting and lifting was correct, but then I saw the double hit, 8/4* 6/5*
I figured this might be the correct move although a bit risky, but it's early in the game and
black has a good chance at covering one of the blots even if he is hit.

I ran this position through XG and saw that 8/4* 6/5* is the only correct move while everything else is a huge blunder.
Why is it that the double hit is so strong here and the only correct move versus anything else?

8/4* 6/5* +0.488
8/4* 4/3 +0.111 -0.377
22/21 8/4* +0.075 -0.413
8/7 8/4* +0.055 -0.433
22/18 6/5* +0.008 -0.480

I would have got the move right, but mostly from seeing similar situations before. Here I would guess it has a lot to do with the 2 exposed blots on 14 and 15.

Even if white gets one blot out, you probably have a double/drop.

More experienced players will hopefully be along shortly with more detail.

Classic case of Magriel's safe vs. bold evaluation. Better homeboard - check. Anchor - check. Fire away

I look at it this way. After 8/4*, what do you risk more by hitting second checker with an ace? Not much. You're only screwed after the 54 double hit. Opp's 5s were quite good already (anchoring up) after the single hit. And the gains? Over the roof. Take note that if opp hits one of your checkers, he often dances with his other guy, and you have plenty of cover or attack rolls (even if he doesn't dance and enter both, you can still continue the attack). That's already OK. Now look what happens if he doesn't hit at all (16/36 chance). Over the roof.

Factors like:
- you outboard your opponent
- after double loose hit you reopen the priming plan (very improbable before the roll), slotting all important gaps
- opp has a dynamic frontal structure (may improve quickly given full rolls to play)

...raise the urgency and value of an attack even farther, but are not decisive ones.

The double hit is so strong that it's quite hard to find a variant where it's not the top choice. Take a look at bunch I've examined (eval by XGR++):


Opp doesn't have additional blots exposed.
8/4* 6/5* is still better than 8/4* 4/3 by .139


Opp doesn't have add. blots, plus we don't outboard him anymore. Also, his board/prime is quite strong, so getting hit is more risky.
8/4* 6/5* is still better than 8/4* 4/3 by .136


We are given a very constructive ace on the other side of the board, anchoring up against an already strong blockade.
8/4* 6/5* is still better than 22/21 8/4* by .113


Packing up opp's frontal structure with builders greatly raises the urgency to anchor up. Even in this situation...
8/4* 6/5* is not worse than 22/21 8/4* (they are +/- .001)