From MLB Power Pros Wiki

Item Description

Secrets of Pitching is an item in Success Mode 2007 and 2008. It will appear as a red book icon on the inventory screen, and can be used to acquire a random pitching ability.

The book is not sold at Bison's Shop but can be found inside a Surprise Bag, or obtained from various events.

Possible Abilities

Secrets of Pitching can potentially give any blue pitching ability except 5-Scale Abilities (Fastball Life, Spin, w/RISP, VS LH Batter, Release, Recovery, Poise) as well as Intimidator and Gyroball.

In addition to blue abilities, it can also give the neutral ability Poker Face.

Baseball Books
Secrets of Hitting | Secrets of Defense | Secrets of Pitching | Legends of Baseball