Comment by skribb

Could probably do an elo system and sample pairs. E.g.

1. Set the elo of all CVs to 1000 elo

2. Randomly pair up CVs and compare. Winners gain elo, losers lose elo.

3. Repeat #2 for a few iterations, then remove bottom X% of CVs.

4. Repeat 2-3 until the amount of remaining CVs is small enough to do an exhaustive comparison.

I don't have a mathematical proof, but I suspect that this is a decent cost-effective approximation of comparing every pair (depending on the parameters)