Bill Lish mentioned an excellent vehicle to develop concentration and focus. Don't limit your reading to bowling books per se. First of all, focus and concentration are essential to most sports, second, aside from the Dean Hinitz book, there's been precious little text devoted to this aspect in bowling text. Cruise through your local book store or used book store, spin through some martial arts books, some sports psychology books, coaching books (any sport). The Inner game of Tennis by W. Timothy Galwey (spelling) is a very good book to start with.
Here is a link to a few short articles on the mental side of sports.
http://www.pbs.org/saf/1206/resources/resources-2.htm
There are several articles that are worth your time,
none of them are long so don't worry about a time commitment. There's a bit on right brain/left brain processing.
Funny, I had two coaches ask me about one of the Professors, Rolf Gauger (during a personal lesson when he was trying to make a bowler out of me - finally he realized he was a coach and not an exorcist!!) and Susie Minshew via e-mail. If they were interested, you should be too.
Do not discount this aspect of your game no matter what level you are at!
If you are reading this during the holiday season, hope you're having a great one!
Have your best year yet in 2004!
Take care.
"Great minds discuss ideas; Average minds discuss events; Small minds discuss people."
Eleanor Roosevelt
Be well, John K. in Glendale Az.