Whenever a horse makes a forward move toward an old top, the handicapping decision is whether the move indicates that more forward movement is imminent or whether the horse figures to react from the effort.
There are a few guidelines that I think can help in estimating which result is more likely, leaving aside the special cases such as the recovery patterns that have been discussed.
1. Horses who have previously shown to be hard hitting and able to make forward moves immediately after forward moves are better gambles.
2. A horse whose forward move was four points or more off its top is more likely to move forward again.
3. A horse whose forward move was three points or less from its recent form level is less likely to improve again.
The attached Sheet (Barnacle Jim) is a good example of a horse who fails all the tests. His prior history indicated that any significant effort is the end of the line. He is gappy and has never gotten back to a peak performance in the same grouping.
His last number is only three points off his top and is a substantial move from his only other starts this year.
Barnacle Jim was about 5-1 in a race where the 14 was competitive, but I think he was a good bet against. I would estimate that 17 and up was an 80% plus likelihood. I think that it is now true that betting horses to bounce off of weak secondary efforts has a higher percentage chance of being right than betting horses to bounce off of tops (except where the top is truly ugly).