ROTW went faster than I thought, so--
1-- If you have just one grass race on the day, you are going to do it off the horses in that race, so it doesn\'t matter what the rails are. If you are going to compare two races on the same day, you need to know it\'s apples to apples, so you need to know what\'s going on if you are going to combine them. Some places use turf rails, but run exact distances. In those places the rail doesn\'t matter, but
2-- NYRA (for example) uses turf rails, and runs exact distances. Certain rails create unusual run-up situations-- specifically, for the inner turf 1 1/16th, since with no rail the gate gets backed up almost to the back of the chute, leaving only a very short run-up. This changes the relationship between that race and those at other distances-- not because of the rail, because of the resultant run-up.
3-- I touched on this before in a response to CH, but turf figures are different than dirt figures. For starters, the pace is much slower, so there are more races where the final time is not \"true\" (resulting in \"s. pace\" races). Fortunately, grass horses are EXTREMELY consistent, and usually run in tight ranges. This makes it easy-- you go by the horses within a race if they have a significant grass history, and don\'t have to extrapolate to any serious degree
4-- EXCEPT in unusual situations, like when the only grass race on the day is for 2yo maidens that have never run on grass. Depending on the situation, you might just be screwed, which is when I leave a box. But if I am going to extrapolate, I\'m going to make damn sure that I\'m dealing with apples in both cases-- same grass course (not inner/widener), both exact distances, similar run-ups, no major differences in pace, etc.
5-- In general, they do less to grass courses than dirt, which means if there is no weather between days, they are more likely (but far from a sure thing) to stay about the same same speed. If I\'m in a situation where I need to use surrounding days, I would prefer that the course be the same speed for the days on both sides. If I don\'t have that-- or if weather on one side screws things up-- I won\'t tie it to just one day unless doing that also fits well with the dirt figures the horses have run.
The two sides of the house I can see are white. Make as few assumptions as possible.