The tenth inning stretch: Prospects

6/2/08

Prospects

I've always believed that prospect lists have been (more that somewhat) arbitrary. Being a number person, I wanted to devise a formula that could actually put a numerical value to support a prospect ranking.

Here is the results of a first take of my formula that takes in account the following:

Performance at the end of the year
Performance vs the average league pitcher/batter in several categories
Fielding Performance for Batters (compared to an average major leaguer)
Improvement related to last year's performance (a factor that is somewhat passed by in most rankings)
Level of play (A, AA, AAA, higher is better)
Promotions to higher levels of play
Age (younger is better)

All of these factors are weighted differently.

The results for the end-of-year 2007 (i.e. 2008 results not into consideration) prospects of note in the Twins' system:

Pitchers:

Delaney 0.582*
Slowey 0.443
Gabino 0.385
Blackburn 0.365
Craig 0.347*
Robertson 0.332
Bass 0.297*
Duensing 0.248
De Paula 0.210
Burnett 0.204
Lahey 0.168
Rainville 0.152
Swarzak 0.146
Manship 0.141
Sosa 0.141
Van Mil 0.122
Hernandez 0.121
Mullins 0.095
Morlan 0.092
Fox 0.085
Mulvey 0.056
Mijares 0.051
Pino 0.042
Guerra <0
Humber <0

Batters:

Pridie 0.329
Morales 0.296
Buscher 0.285
Macri 0.221
Sergio Santos 0.189
Hughes 0.183
Romero 0.172
Johnny Woodard 0.157
Tolbert 0.129
Garett Guzman 0.112
Brian Dinkelman 0.102
Ramos 0.082
Steven Tolleson 0.073
Valencia 0.066
Brock Peterson 0.038
Span 0.019
Dustin Martin 0.029
Plouffe 0.009
Casilla <0
Singleton <0
Parmalee <0
Lis <0
Revere etc N/A (only one season pro ball)

Notes:

* denotes pitchers whose somewhat surprising high ranking is helped by major improvement (this is not to say that they had league average or worse numbers; as a matter of fact they all have much better than league average numbers). Are those people overlooked, or the formula needs tweaking? Probably both. I know that the formula needs tweaking, but take Delaney for example. He finished 2007 with an ERA of 1.03 and a WHIP of 0.86 had 16 BB and 83 Ks in 70 innings. No matter what he should be very high in this list.
I like that the numbers make some sense comparing pitchers to batters. It is true that the Twins system is richer in pitching prospects that batter and this is reflected here
Some refinement with the weights is needed. The actually formula penalizes people who have digressed, even if the played in higher levels (see Humber or Lis for examples); on the other hand 0 and <0 denotes average and below prospect...
When there are significant numbers I will run again for 2008
Cutoff age was 26 years old at 2007
I need to refine it so it includes first year prospects. As is to be included a prospect should have played 2 years of pro ball

here is my very preliminary top 25 list, at the end of 2007 season.