I posted about this in the Intimidator/Gd Delivery thread but I thought since it was a general strategy for pitchers it deserves its own thread. I'm not the one who came up with this, I only read about it on the Gamespot forums and fell in love with it after trying it out.
Generally speaking, you can save a lot of points by gambling for velocity or breaking ball levels, but you end up paying the full amount for most of your stamina and control upgrades. I like to think of it as "stuff" vs fundamentals - You can upgrade pitcher's "stuff" through gambling but the only way to improve stamina and control are spending more points on them.
The approach this strategy takes is to get the "stuff" upgrades part over quickly, so that you have more turns and exp points to spend on your fundamentals. Gambling every turn for either velocity or movement is good, but using the method shown here you get to gamble for both velocity and movement on every turn during a certain stretch of your schedule. This way you acquire velocity and movement twice as fast, thus enabling you to spend more turns boosting stamina and control. Pretty astonishing when you think of it in numbers: It only takes 15 turns to go from an 80mph 1CHG scrub to a 95mph 7CHG 5CB 4SLD ace. Isn't that great? Once you set aside 15-20 turns (approx 4-5 months in game time) for boosting your "stuff", you can allot the rest of your entire college life to dating, working and boosting your other stats!
The specifics are that you keep doing Shadow Pitching (+4 strength +12 technique +4 breaking ball) every turn during a certain stretch of your schedule. The Recovery Necklace is helpful but I assume if you're a Gambler you already knew that. Anyway the important thing is this: as long as the required tech points for a +1 mph velocity upgrade stay below what you get from the Shadow Pitching training, you can spend your strength and tech points to first gamble for +1 mph, then use the remainder of your tech points with the breaking ball points to gamble for +1 movement.
The cost of upgrading velocity will increase gradually, but so will the amount of technique points you gain from Shadow Pitching, as long as you don't rest or practice something else. That's how you can sustain this run for as long as necessary.
Since Shadow Pitching won't give you any mentality points, you need to stock up on those (for gambling on the breaking ball upgrades) before you begin. Also, during this run you won't have any extra strength points to spend on stamina, so it's recommended that you already have sufficient stamina before proceeding.
Considering these two points, it seems to work best if you work the Shadow Pitching run into your second year, after focusing on strength training in your first year (which will give you stamina, and also load you up with mentality points). Needless to say it helps to have a Gambler's Ring, another reason why you should do it in your second year (assuming you get the ring via Annie's Surprise Bag).
Example Player: 105mph C188 S196 7/7/4/4 with Intimidator and high fielder stats
(PS2)
The tech point bonus for Shadow Pitching tops out after a while, so even with Gd Sense, both Focus Stones the Champion Ring and the Chocolate Sponge Cake, you won't be able to do it past 96mph.