[Christ]

If I had to guess, I'd probably say it has something to do with how far you go before you hit the neutral detent.

For instance, on my TwinStar, N is all the way down, half click up. On mine particularly, that half click happens closer to 3/4 of the way up, if not a little further. Sometimes, I actually get it into 2nd instead of N, but I can tell by the feel of the click.

I would say that bolt probably adjusts how far up the lever goes before actuating neutral.

The only other thing I can think, and I wouldn't imagine it being correct, is that it adjusts neutral to some other position between gears. Again, I'm sure that's not even close to correct.