Will Mark McGwire break Hank Aaron's home run record? Can Derek Jeter crack 3,000 hits? What about Roger Clemens -- can he reach 4,000 strikeouts?

Tired of sportswriters speculating on such topics, sabermetrician Bill James concocted a relatively simple formula for assessing the career of an individual. It quickly became his 'Favorite Toy'. The formula takes into account a player's current statistics, their projected totals, and their age to determine the percentage chance of reaching a certain milestone. Let's assume that it's 3,000 hits.

Needed Hits. How many hits does the player need to reach the specified goal? (Milestone - Current Total)

Years Remaining. Defined as (42 - Current Age)/2. Any active player is given .5 seasons, regardless of age. Players who had at least 100 hits and an offensive winning percentage of .500 or more, they're given 1.5 seasons. If a player matches one of these criteria, he's given 1 season.

Established Level. Take the number of hits in the previous season * 3, plus the number of hits in the season before that * 2, plus the number of hits in the season before that, all divided by 6. If this value is less than 80% of the number of hits in the previous season, bump this value up to that number.

Projected Hits Remaining. Established Level * Years Remaining.

After all this is calculated, divide Projected Hits by Needed Hits and subtract .5. This is the percentage chance the player has of reaching the goal. As an added measure, the chance for a player to reach a given goal can't be greater than .97 to the power of Years Remaining.

Using Favorite Toy, let's calculate Nomar Garciaparra's chance for 3000 hits. First, Needed Hits. Nomar's got 812 hits, so he needs 2188 to reach 3000. He's 27, which translates to 7.5 seasons remaining. His established level is (197 * 3 + 190 * 2 + 195)/6, or 194.3. Projected Hits Remaining: 7.5 * 194.3, or ~1457.

So, Nomar's chance of reaching 3,000 hits is (1457/2188 - .5), or 16.5%.

Here's another one. What are Mark McGwire's chances of breaking Hank Aaron's all-time home run total of 755?


((42 - Current Age)/2) * (2000HR * 3 + 1999HR * 2 + 1998HR)
------------------------------------------------------------- - .5 = 
                  6 * HR_Needed

2.5 * (3 * 32 + 2 * 65 + 70)
---------------------------- - .5 = 11%
       6 * 202
One of the faults of Favorite Toy is that it relies on exact age. For that reason, Mark McGwire's chance of reaching 756 home runs dropped 12% overnight when he turned 37. For that reason, Favorite Toy numbers are usually generated immediately after the regular season.

Some Favorite Toy numbers (from the end of the 2002 regular season, except where indicated)

% Chance Of Reaching 756 Home Runs    
==================================
Barry Bonds                     48
Sammy Sosa                      45
Alex Rodriguez                  42
Ken Griffey, Jr.                 6
Vladimir Guerrero                6
Albert Pujols                    2
(HR stats taken from baseball-reference.com)

% Chance Of Reaching 2298 RBI (From 2000 Season)
==================================
Ken Griffey, Jr.                25
Manny Ramirez                   16
Alex Rodriguez                  15
Sammy Sosa                      14
Vladimir Guerrero                9
Carlos Delgado                   5
Juan Gonzalez                    3
Todd Helton                      3
Jeff Bagwell                     2
Frank Thomas                     2

% Chance Of Reaching 300 Wins
=============================
Greg Maddux               100*
Tom Glavine                42
Pedro Martinez             24 
Barry Zito                 15
Mark Mulder                11
Mike Mussina                6
Tim Hudson                  3

Obviously, the chance can't be 100%, but according to the statistical tool, it is.
Maddux and 300 is as close to a lock as you can get.