You’re referring the to AMA national event at Budd’s Creek, right? It’s about an hour away from Washington where I live, so figured it would be fun to catch it. A great day, until it started pouring during the final 250cc moto. Walking a 1/2 mile back to my car in it was a real thrill… 
I noticed the head turn thing as well, but I think it’s because on a track, you know where you’re going and you know that the other riders do as well. Also, there can be huge grooves in the track, etc. so you really do need to keep your eyes on what you’re about to get into. But I dunno for sure…
Also interesting to see how as they approach a turn, they’ll kick their inside leg straight out forward, to plant in the turn if needed. Also liked when jumping, they rev the engine when just about to touch down.
Walking around the track during the races, it was interesting to me how for any given turn, there’s often more than one “line” through it, and the riders try different approaches. One turn in particular had a small hill on the very inside, and a regular bank on the outside. Some riders would slow down and snake over the hill, others would go faster and go into the bank at the outside.
I found the racing at times hard to follow, as everyone gets pretty spread out on the track…but watching the technical abilities of the riders was inspiring, and made me wish I had a dual-purpose bike! The track does track days, and even has a motocross school (they had a big tent outside)…I’m definitely tempted, but like Safetyfirst, it’s more gear, and I’m still buying new street stuff as it is…
