Had this position come up in a recent match. I was stumped. What's your play?

I go with 8-4, 6-5. Keeps back anchors and slots the 5.

I would not touch back anchors and try to play as pure as possible.
Slot 5pt for sure and unfortunately 8/4.

13/9 looks more pure but I am not sure I need that much timing (what we have now + 10 + 12 if both are hit).

I concur with noncarborundum and deh, although I would have said that breaking your midpoint without an excellent tactical reason is rarely good.

I disagree. The timing is horrible for this position. So we will either have to give up one of the anchors and turn this into a holding game or play pure. I would elect for the pure play, 13/9 6/5. Additionally 8/4 with the 4 is making already bad timing worse.the only place to go now for that checker is deep in your board and in back games you don't want checkers deep in your board until moment of climactic contact. That is the rolls right before your opponent stands to leave your game winning shot.

So I ended up playing 8/3 here. Slotting the 5 seemed like a nice idea, but stacking the 4 point looked wrong to me. Afterward, I did some rollouts and found out that 13/9 6/5 was the correct play, which I wasn't even close to choosing! The other option I was considering was 8/4 6/5, which turned out to be 2nd best here.

I noticed that Bill has a discussion in Modern Backgammon about a similar play. In diagrams 2-8 and 2-9, he talks about why splitting the midpoint is worth the risk. But the difference is, in those two positions, black is leading the race and trying to bring home the win. In my game, I was very much behind (+40) and giving up my mid board when I was trying to play catch-up seemed unreasonable to me.

I'd love to hear some thoughts from Bill and/or others about why giving up my mid board is the best play here. I understand that my anchors are strong, but I felt like I was going to starve my homeboard of builders by giving away those extra checkers, which would lower the threat of my back game in the end.

9 and 5 all day. Pure Pure Pure in this position

So you're only down 40-some pips in this position. It's not enough to hold 2 points in the long run, anyway. One of two things will happen from 9 and 5:
1. He hits more guys and now you're down 60-80 with easily circulating spares - you'll have timing for days. There's also no risk of becoming overtimed because he can't keep you dancing forever with his board and you already have 5 slotted.
2. He doesn't hit any more guys. In this variation, the right strategy will become to give up the 20 eventually and you will have a reasonable deuce-point game against a gapped position.