Doc, I think you should consider discontinuing using Auto ISO for night games and figure out the proper exposure for the home team stadium, including ISO. I say this because the lighting is constant and not changing, correct. You stated that you shoot for the college and I assume you shoot all of their home games. If this is the case, you should be able to establish the proper exposure for the stadium and every time you shoot there, you just use the same settings (look at your photos exif to get an idea of the ISOs). Once you get the proper setting, just set it and forget it. Ex. set your camera to f2.8, SS 1000, ISO, shoot one of the players and check the exposure on the back of the camera (i.e histogram). Auto ISO will change ISO just about every time you point your camera at any different part of a player. If you use LR, you can filter by exposure and see how many times ISO changed during the game. To make changing ISO easy for me, I have ISO on my Set button, which allows me to change it very quickly when needed without looking at the back of the camera or removing my hand from the camera (hold the set button and spin the main dial), but since I have the correct exposure, I haven't needed to make any changes. Btw, you can get away with SS 500-800 (I don't go below 800 though). Also, using the same exposure allows easier and faster editing because the exposure is the same for all shots (thinking batch processing).
Note: If there are some dark areas on the field (I assume the lighting is pretty decent since it's a college) you can quickly adjust ISO to compensate, but to be honest once you get the proper setting you should be good.
Just so you know, I am not making these statements without having done so myself. I am now shooting night games as the county is starting to install lighting at many of the HS team fields. I had to figure out the setting for this one particular field and now when I go, it's automatic; f2.8, SS800, ISO 8000 or f2.8, SS 10000, SS 1000-1250. Ironically, I asked another photographer what his settings were and they were the same. Below are some samples.
http://www.methodicalimages.com/p1184877 (this game was f2.8, SS1250, ISO 10000 and 12800)
http://www.methodicalimages.com/p589940474 (this game was f2.8, SS800, ISO 8000)
Just One Man's Opinion.