I must be. Maybe I overestimated what it takes to be an 18 cap. I'm coming up with something similar to you - but it doesn't sound right to me.
You are saying that someone who averages 20 over can be an 18. And by your count, the 7(bogeys) + 10 (doubles) + 1 (triple) gets him there. Which obviously it does. But it seems unlikely to me that a person who hits double or worse on 6 of the 18 holes gets that many pars per round and a birdie every other round.
But by my numbers, it's even worse. I've heard that a person plays to their handicap once every 5 rounds or so. And if so, I doubt they would shoot within 2 shots of it on average (which would be your 20 over). I don't know what the answer is, but in my math above I estimated more like 23 over as the average. By his own stats, his average is 23.82 over. By these numbers, he would need to go from 6 or 7 over par after 12 holes - then go to almost 24 over in those last 6 holes - or about 18 over for these 6 holes. That is triple bogey for all 6! Who makes triple bogey for a third of your round on average, but is good enough to get 5 pars and a possible birdie?
Does that sound common to everyone? Maybe I am having trouble getting my mind around it because I just play a different style of golf than he does. I am close to an 18 now and was right around 18 for about a year. And in my experience - if I get 4 or 5 pars and maybe even a birdie in a given round, I'm basically shooting or breaking 90 that day. And Max is doing this on average - but shooting 96.
I seem to be the odd man out, and hijacking the thread, so I'll drop it. But when I read it - the numbers didn't work for me and I thought it was interesting.