For a simple reason. Nega-scout search algorithm,fractional extention,selective research,razoring, with a seemingly working null search. Implementing a good evaluator may be the most difficult part of chess programming. Adding a little to TSCP could bring down the nps from 35,000 to 20,000 nps resulting in a weaker improved program. No hash table.
All time controls.
It prints a log file giving the nps, time, depth searched after each move.