I was thinking of the case where all of a player’s opponents are rated so low that the player gains only a small fraction of a point (say 0.02 or so) from each. In this case, in the pre-FP days, rating changes were always rounded away from zero (please correct me if I’m wrong), so a player who beat up on weakies was guaranteed to gain at least one rating point. But with FP, no rounding is done, so the player would likely need to be perfect in many consecutive events, right?
That would make a difference, to be sure. But then, with the rating differences being not quite so extreme, the player might be in danger of drawing a game with a player 300 points below him, and that would surely throw a big monkey wrench into his plans.
BTW, do the ratings really use floating point? Or is it just fixed-point with 2 decimal places? (Not that it would make much difference, I suppose.)
I believe PHP and postgresql both use the IEEE floating point representation, which is probably good to 6-8 digits to the right of the decimal point for numbers in the range of 100 to 2999.
In the cases we found several years ago, the players were often gaining 1.5 to 3.5 points per event before rounding away from zero in the conversion to integers. Going to FP would slow them down, but not stop them from inching upward.
I did do some looking and did not find any obvious recent cases of players who have been moving up on a diet of small fish. There still could be some, constructing a query to look for them isn’t easy. (As I recall, the way we found them last time around was after an inquiry by a member about a specific individual. Once you have an example, finding a pattern is a bit easier.)