Posted by on Jun 12, 2010 in Baseball

Back in the early 90’s, when I was collecting baseball cards and trying to find the next superstar, I started getting into stats and number-crunching. That’s how I learned to use Excel.

I first got into it when spotting Manny Ramirez’s gaudy high school baseball numbers. I figured there must be a way to analyze some of these numbers and run some sabermetric formulas on them to figure out who was going to be good. If I could buy the right rookie cards, they might be good investments. So I started looking at stats of young players (mostly on the backs of baseball cards, and later Baseball America) and used Excel to come up with different ways to weight and analyze the numbers.

I started getting pretty confident with what my “prediction” formulas were spitting out. My numbers in 1991 screamed that Manny Ramirez and Chipper Jones and Frank Thomas and Jim Thome were going to be big stars. Keith Mitchell, in particular, was supposed to be the second coming. Unfortunately, they screamed that Brian L. Hunter and Francisco Cabrera and Rich Aude would be big stars, too.

In the ensuing years, card companies were making it impossible for the average collector to keep up. I began to realize that all my alphabetized rookie cards in plastic sleeves were pretty much worthless, and that all the time and energy I had poured into my baseball card collection was pretty much a waste. With that, I lost interest in prospecting. Instead, I turned my baseball attention to a new numbers game, a historical simulation league called the HOFL, and that’s kept me busy since 1995.

The New Hype

At the beginning of the 2010 season, Jason Heyward came onto the scene with more hype than most rookies in recent memory. I felt a little tickle down below, knowing that I could probably take a closer look at the numbers and figure out, “How good IS this guy, really?”

So I fired up Excel and took a close look at Heyward. Once I was at it, I found a bunch of other names to plug in to compare. Back in the day, I knew half the players in AAA, but now I found myself entering names I had mostly never heard of.

I’m a lot smarter now. I know things about how players grow and develop that I didn’t really understand back in the day, and there are things you can look for in the numbers that didn’t occur to me in the Keith Mitchell days. So I kicked around some ideas, crunched some numbers, and came up with some new formulas that might be better at predicting minor leaguers will be able to hit in the majors.

The Formula

My formula takes into account the kind of power a player showed in the minors, with the projection that some of their doubles and triples in particular might turn into additional homers as they get bigger and stronger. It also takes into account a batter’s “eye” by preferring guys who are able to draw a walk and avoid the strikeout. If they don’t have an eye in the minors, they’ll usually (but not always) get hammered in the majors. Lastly, I look at age. Guys who get to the majors quickly are usually much better than guys who linger in the minors since a) the fact that they were rushed to the majors usually means that they are something special about them that may not be reflected in the stats, and b) they get to spend their formative years playing against the best of the best.

Here’s the nitty gritty, in case you want to try setting up your own spreadsheet:

Power Potential = (1B * 0.5 + (2B + 3B) * 4 + HR * 6) / AB

Y Score (from Bill James) = 24 – (age * 0.6)

Years of Improvement = MAX((28 – Y Score), 1)

Age Modifier = Years of Improvement ^ (1 / 10)

Eye Modifier = LOG(BB / SO, 100) + 1

Prospect Score = Power Potential * Age Modifier * Eye Modifier

After all the numbers are crunched, the final score, by chance, works out to look a lot like a slugging percentage. According to my system, a .400 guy is not that great of a prospect, while a .800 guy is a real slugger.

But it’s not perfect. So that everyone is ranked on the same scale, I only use minor league stats. Minor league stats are sometimes incomplete. And the numbers I use are not normalized for level, league, or park, so batting .350 for A-ball High Desert counts the same as batting .350 in the AAA Durham. When I can get reliably normalized minor league stats, I’d love to run the numbers again.

Also, there’s an assumption that players are promoted according to their ability, so that they are always facing equivalent competition. This is generally true in most cases, but when there’s a guy festering in A-ball and killing it vs. another guy lingering in AAA and struggling, the A-ball guy will “look” significantly better even isn’t necessarily better.

And for now, I’ve just looked at batters. Maybe pitchers will come next, but pitching can be a little trickier to predict in a lot of ways.

Today’s Future Stars

Who are today’s future stars? Let’s look at current minor leaguers and recent call-ups and see which of them are most likely to hit in the majors:

Name Year Age Score
Reynaldo Mateo 2009 19 .878
Jerry Sands 2010 22 .840
William Myers 2010 19 .838
Evan Sharpley 2009 22 .823
Buster Posey 2009 22 .809
Cody Decker 2010 23 .803
Matt Wieters 2009 23 .801
Alex Gordon 2010 26 .785
Mike Stanton 2010 20 .779
Kyle Conley 2010 23 .771
Matt LaPorta 2010 25 .766
Dillon Baird 2010 22 .752
James Darnell 2010 23 .750
Jared Clark 2010 24 .745
Jaff Decker 2010 20 .740
Gordon Beckham 2009 22 .739
Daniel Nava 2009 26 .737
Carlos Santana 2010 24 .732
Pedro Alvarez 2010 23 .729
Jason Heyward 2009 19 .723
Carlos Ramirez 2010 22 .721
Chris Carter 2010 23 .717
Kyle Russell 2010 24 .717
Paul Goldschmidt 2010 22 .712
Michaelangel Trinidad 2009 20 .709
Mike Zuanich 2010 23 .705

Mateo, Myers, and Sharpley have barely played, so they’re definitely iffy until they get more playing time under their belts. Sands looks solid, and he’s killing it this year. Posey and Weiters are already establishing themselves in the majors. Alex Gordon, for some reason, is trying desperately to keep a major league job. Why can’t he hack it? Mike Stanton looks like he’s for real. Carlos Santana just made his major league debut today. I’ve pined over Jaff Decker in the past, but he’s been screwing the pooch this year, so he’s moved down quite a bit. And there’s Jason Heyward, barely making the top 25. He very well could be one of those special guys who was rushed through the minors and never got a chance to stick around and kill it. Time will tell.

There will obviously be a few surprises both ways, but I’d feel pretty comfortable betting that the top 10 or so will become quality major league hitters. Check back with me in 5 years.

For shits and giggles, I plugged in Bryce Harper and his junior college numbers. Off the charts at 1.720. But junior college doesn’t mean squat. I can’t wait until he gets some pro experience so that I can plug those numbers in.

Yesterday’s Future Stars

After comparing today’s rookies, I decided to go back and add today’s stars to give me a glimpse of what they would have looked like as rookies. How did guys like Ken Griffey Jr. and A-Rod rank when they first came up? What about stars of the 80’s, like Mark Grace and Darryl Strawberry and Jack Clark? And the highly touted rookies like Gregg Jefferies and Todd Zeile? What about those fringy guys who could kill it, like Ken Phelps and Ron Kittle? I was really curious how all these guys would compare with each other as rookies.

According to my numbers, here are the top 25 historical minor league future stars of the last 30 years, listed with with the player’s first real season in the majors. Interesting to see who panned out.

Name Year Age Score
Travis Lee 1997 22 .929
J.D. Drew 1999 23 .899
Manny Ramirez 1993 21 .899
Ken Griffey Jr. 1988 18 .881
Albert Pujols 2000 20 .874
Troy Glaus 1998 21 .862
Mark Teixeira 2002 22 .857
Gary Sheffield 1988 19 .850
Darryl Strawberry 1983 21 .837
Vladimir Guerrero 1997 22 .837
Ken Phelps 1980 25 .826
Lance Berkman 2000 24 .819
Alvin Davis 1983 22 .818
Pat Burrell 2000 23 .815
Mark Grace 1988 24 .815
Alex Rodriguez 1995 19 .803
Gabe Kapler 1998 22 .802
Billy Butler 2007 21 .800
Greg Vaughn 1992 23 .798
Barry Bonds 1986 21 .793
Frank Thomas 1990 22 .793
Jeremy Giambi 1998 23 .788
Carlos Quentin 2006 23 .781
Andruw Jones 1996 19 .778
Tom Brunansky 1981 21 .769

Any surprises here? I think so. Travis Lee fucking killed it in the minors, but that was with limited playing time, lingering in a hitter’s park in a hitter’s league in A-ball for longer than he probably should have. Even in the 80’s, I knew Phelps could hit but was never really given a chance. Alvin Davis is a bit of an enigma. He should have been even better than he was. What happened to him? Drugs? Injury? Burrell was good for a short while but seems to have petered out. Kapler had more potential than I thought. How come he never put it together? Billy Butler’s for real. Jeremy Giambi? Did he disappear because he stopped using his brother’s steroids?

Everyone else seems to fall more or less where I’d expect them to fall.

The Historical Best

Some other names that are fun to look at:

Name Year Age Score
Willie Mays 1951 20 .949
Willie McCovey 1960 22 .818
Paul Molitor 1977 20 .798
Jack Clark 1976 20 .761
Randy Ready 1985 25 .751
Gregg Jefferies 1988 20 .751
Ron Kittle 1982 24 .746
Andre Dawson 1976 21 .746
Will Clark 1986 22 .738
Ryan Zimmerman 2005 20 .733
Jason Giambi 1995 24 .733
Mark McGwire 1986 22 .732
Jim Thome 1993 22 .719
Todd Zeile 1989 23 .717
Tony Gwynn 1983 23 .712
Willie Aikens 1978 23 .708
Thurman Munson 1969 22 .708
Nick Johnson 2001 22 .699
Don Mattingly 1983 22 .698
Justin Morneau 2004 23 .692
Chipper Jones 1993 21 .692
Josh Willingham 2005 26 .691
John Kruk 1986 25 .689
Jose Canseco 1985 20 .687
Nomar Garciaparra 1996 22 .686
Roger Maris 1956 21 .686
Todd Helton 1997 23 .684
David Ortiz 1999 23 .675
Eric Davis 1984 22 .673
Eric Anthony 1991 23 .666
Rick Ankiel 2005 25 .649
Marv Throneberry 1957 23 .643
Jack Cust 2007 28 .635
Mike Piazza 1992 23 .631
Mike Schmidt 1972 22 .624
Robin Yount 1973 17 .622
Pedro Guerrero 1979 23 .608
Ruben Sierra 1986 20 .603
Glenn Davis 1985 24 .602
Jeff Bagwell 1990 22 .596
Morgan Ensberg 2003 27 .577
Fred McGriff 1986 22 .574
Cal Ripken 1981 20 .573
Earl Averill 1958 26 .573
Dave Pope 1960 39 .569
Joe Mauer 2004 21 .557
Willie Stargell 1962 22 .548
Bobby Abreu 1997 23 .538
Harold Baines 1979 20 .538
Charlie Peete 1956 27 .528
George Brett 1973 20 .518

Look at Willie!

Amazing how some of these guys, like Brett and Schmidt and Yount, were able to step it up when they got the majors, presumably without steroids. But again, look at how young they were when they made it. They were something special and they were rushed along.

It’s interesting to see where some of the other names fall on this list. An argument can be made that some went on to flourish in the majors because of steroids…

The Bottom of the List

And now, the lowest rankings I came up with. I haven’t run all the numbers in baseball history, so I’m sure there are lower results out there.

Name Year Age Score
Matt Bush 2007 21 .275
Terry Blocker 1988 28 .313
Humberto Quintero 2009 29 .324
Alcides Escobar 2009 22 .335
Placido Polanco 1999 23 .346
Ivan Rodriguez 1991 19 .362
Tommy Manzella 2009 26 .365
Brian L. Hunter 1995 24 .370
Dave Rohde 1991 27 .383
Garret Anderson 1994 22 .387
Alan Trammell 1977 19 .389
Scott Beerer 2010 27 .400
Darren Lewis 1992 24 .401
Ray Knight 1976 23 .406
David Wright 2004 21 .415
Michael Bourn 2006 23 .417
Hector Gomez 2010 22 .420
Martin Prado 2007 23 .421
Jesse Barfield 1981 21 .422
Raul Mondesi 1993 22 .423
Luis Terrero 2010 30 .424
Ian Desmond 2009 23 .425
Mark Loretta 1995 23 .430
Javy Lopez 1993 22 .430
Chris Burke 2007 27 .430

Some of these guys were highly touted amateurs who just plain sucked. Some of them were victims of being rushed (Trammell, maybe others). But given how much a few of these guys improved in the majors, a case can be made that some of these guys also used steroids…


  1. Energized by Bryce Harper’s debut, I wanted to check in on this… After promising starts, lots of guys are struggling.

    – Jerry Sands has seemingly lost his ability to hit. Will be interested to see if he can turn it around.

    – Alex Gordon did last year what the Royals and I have always expected from him, but he seems to have returned to sucking this year.

    – Mike/Giancarlo Stanton is definitely is for real, although off to a slow start this year.

    – Carlos Santana is not amazing yet, but his peripheral numbers look good and Cleveland was confident enough to sign him to a long-term deal.

    – Jaff Decker has fallen off the wagon but is still young.

    – Jason Heyward may in fact be overrated.

  2. Took a first look at 2012 numbers last night and came up with some fresh names to watch. My very early pick for future star is Joey Gallo.

    The 18-year-old has only batted 200 times in rookie ball, but it’s a very impressive 200 times.

    Others off to hot starts and near the top of my list, all with very limited playing time, are Mike Zunino, Paul Hoenecke, and Daniel Vogelbach.

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