Probably based on the W/L since he's close to 50/50 while the other guy is up several games percentage-wise. But the only thing that matters as far as the points you gain/lose in an Elo-style system is your rank, so that's what matters.
If you're in USCF chess and you lose to someone 500 points below you, you're going to lose a ton of points. If you beat them you only get marginal gains. You still have to play them, and sometimes there are upsets, but that's how it goes.
That would be fine, if KL lasted long enough for the ELO to even out. Some people, (like me today) will play KL for one day and just rip through the ranks. It sucks for the higher ranked people that lose points because of that weird incentive.
Also because it is so short, the system cannot be sure "where you belong" to any degree of certainty. The system doesn't know where you belong, it definitely doesn't know where your opponents belong, and it grants pretty crazy swings because of it.
They should probably have your ELO be constant across seasons in ranked (even when KL isn't active), so far as who you should play. Ideally, the rewards would be tied to something other than rank, but even if they just changed that one thing, I think people would like it a little better?
You shouldn't have someone who ranked high last season fight people who have never played online before. :-/
