VM Not so good?

I have gone practice sailing several times with a friend who has about the same level of Laser skills as me and we have good sessions - doing windward-leewards around buoys, some reaches out to the channel to be abused by the current and wind holes, etc.

But what I cannot understand is that most of the time during these practice sessions I sail better then him  - pointing higher,  better mark roundings, flatter boat, fewer capsizes, etc.  - but when it comes to race day he does better.  Last weekend, we had 4 short races and I beat him in the first race, the second race I was ahead but touched a mark and he passed me as I was taking my penalty, and then he beat me in the 3rd and 4th race even though I made no big mistakes.  And the prior weekend we split 2 races.

So, what gives? Is he relaxing during practice?  Am I choking in the races? Except for touching the mark last week, I had no dramatic mistakes.  Admittedly in one race I went more right and he went more left on a beat and crossed ahead of me, so I guess that could count as a mistake. But the first and second places in the race also went right, so it seems like boat handling/speed could have been my problem or maybe he caught a nice lift.

I have been concentrating on pointing better in races by anticipating the puffs and staying as close to the wind and flat as possible with hiking and small turns using body weight and small rudder movements where necessary. It has definitely helped and I can see that I am pointing as high as our top sailors, but I wonder if I am pinching a bit and letting overall VMG suffer.  My leeward telltales stream nicely but sometimes my windward ones flop around.

I found a good article on VMG and, even though it involves trigonometry, I will try to read and understand it.