Dennis,
You are of course absolutely correct in stating that one fourty game session is too short a sample to make final conclusions with regards to the value of a one ball handicap between two top flight players. I admit that this conclusion initially may have been premature but I later continued accumilating this kind of data. The overall numbers changed here and there but not to a significant extent. In watching two equal, yet novice players spar, the number of games going to the last ball increased greatly. I also measured the average number of OPEN racks various players needed to win games. In other words, given an open table with a clear and easy shot, how many balls will this player typically run? How many balls will I run on average given the same situation? As an example; if it takes my opponent three open opportunities on average to get out and it takes me an average of two, then I felt I could be far more aggressive with that player. These are the kinds of statisics I find extremely helpful when trying to match up.
When it came to measuring the winning percentage regarding the break I liken this to the serve in Tennis. Player's serves will be broken on occasion but overall the serve should be an advantage to the server. All things are relative.
You are also right in your statement that there are many factors which could be in play in determining the value of the break. I know of many players who never practice their break, and it shows. I was first hand witness to Strawberry's second One Pocket tournament held in Laurel, Maryland where one dark horse player went through a field which included Grady M., Cliff J., and Jose P., as well as a few other prominant players. He did this with the help of an "awesome break" as Jose had commented after losing in the final. This guy broke a ball in an average of three times out of five in each of the race to five matches he played. In mose cases he ran out from the break. In each of his matches he played on a different table. He had practiced the break before the tournament began, experimenting from table to table with various speeds and slight angle changes just to see how aggressive he could get with the break without selling out.
In the end without the advantage of his break he knew he could never have beaten Jose in the final which ended five games to four. In that match he broke a ball in four times running eight and out three times and running six on the fourth occasion.
The break can be an awesome weapon if it is practiced as much as it should be.
Tom