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Finding player comparisons for draft prospects using historical tool grades

Finding the next MLB star using current MLB stars

Houston Astros v Atlanta Braves Photo by Michael Reaves/Getty Images

Oh man, that title isn’t exactly sexy but I’m not trying to hide the idea of this article for the sake of vanity. I think it’s always helpful to 1) work with any data you have or can find and 2) think of different ways to look at that data in a contemporary way.

Over the past few years I’ve either scraped together or collected as they came in as many tool grades given to prospects over the years. I’ve even gone back through some top 100 lists and grabbed grades for players dating back to 2013 (though I could go back further but just haven’t yet - it’s a very manual process). Over the course I’ve collected grades from Baseball America, FanGraphs, and MLB Pipeline. Those three sites have been the most ubiquitous for grades and their approach and staff have for the most part remained steady (FanGraphs has mostly been in the hands of Kiley McDaniel and/or Eric Longenhagen in some form).

I’ll admit the grades have leaned towards FanGraphs recently since they offer an export feature (ie: easier to collect quickly) while others are essentially manually data entry. At some point I’ll go back and add MLB Pipeline are their site is really easy to find older lists. Baseball America has seemingly nuked any prior grades they’ve given out, so it’s lucky I grabbed those when I did before the site re-design.

The method for this is fairly simple-ish and one I’ve done before, called the z-score method (or at least that is what I call it). It requires three steps:

1) Calculate the average value for one criteria (such as the players hit tool grade)

2) Calculate the standard deviation for the same criteria (all hit tool grades)

3) Subtract the value you want to compare to the average from the average and then divided by the standard deviation

When building a comparable based off this method, instead of using the average of all the values we are subbing in the the criteria of the player we are trying to find the comparison to. So if we want Joe Smith’s comparables, we use Joe Smith’s hit tool as the “average” instead of the average of all the hit tools in the database. Then you repeat this for each tool, then sum up the values of all the z-scores, and the lowest total is the closest player to the average (which is again the player we are trying to find a comparison for).

The math isn’t really important here, you just need to know we are trying to find players whose tools are the closest overall to the player we are trying to find a comparison for. One tool can be a good bit off (say: a 40 hit tool vs a 55) but if the others are close, then it will still give us a low z-score.

I’ll be working downwards from my aggregate draft board (I really do collect everything) just like in my names to know list. The grades I’ll be using will be an average of Fangraphs and MLB Pipeline.

Major reminder: I’m going to post the comparable players with no consideration for which position they play, so keep that in mind. I don’t have that data for every player for every year (same with age; another major consideration) so you’ll have to make the mental adjustment when comparing a 50 grade fielding OF with a 50 grade fielding SS.

(please forgive the visual format, it’s a bit crude. Also you may see Fangraphs team and Fangraphs. “FG” refers to the top 100 only list, which often came out before the team lists were finished and grades weren’t 100% finalized. Often the grades were the same but every so often there was a slight difference)

Spencer Torkelson - 1B, Arizona State

Torkelson has a pretty great outcome for his closest comp: Yordan Alvarez, the AL Rookie of the Year. Alvarez is a 1B only whereas Torkelson can play the outfield a bit even if 1B is his likely destination.

Next is Pavin Smith, another college bat who went early (to Arizona at 7th overall) but was never in the conversation for 1.1.

Brett Baty went 12th overall to the Mets last year where he was an older prep prospect with big power and a possibility to play 3B

Eloy Jimenez is one of the more hyped prospects in the past few years (I think - and it’s not a bad thing) as he dominated every level of the minors. He just hit 31 homers as a 22 year old and should improve on the .315 OBP. The only thing keeping him from being a true star is his fielding/DH-ing

Austin Martin - 3B/CF, Vanderbilt

There are some good names on this list: Corey Seager, Franklin Barreto, Keston Hiura, Juan Soto but three of them were younger than Martin, so maybe Hiura is the closer comp, even if the concern for Hiura’s defense isn’t really one for Martin.

Eddie Rosario is an above average player, even with flaws in his plate discipline

Tyler Austin - the closest comp - is an example people often use to point that Yankees prospects are overrated (they aren’t) but he was hurt a lot and jerked around by the Yankees a bit. He’s now played for four MLB teams and just signed a deal with an NPB team.

Asa Lacy - LHP, Texas A&M

Lacy joins the long list of guys with crazy good raw stuff but needing to figure out command. MLB Pipeline is more optimistic on his changeup progression than FanGraphs but the average is probably fair to use there and the same but in reverse for his slider.

Kopech was pretty well hyped (and part of the Red Sox package for Chris Sale) but was pretty shaky in his brief MLB stint and is recovering from Tommy John.

Kyle Wright went 5th overall to the Braves in 2017 and ascended to the majors the next year but hasn’t figured out command at all.

There are a lot of guys with amazing stuff here but it’s a good warning that command matters a lot.

Nick Gonzales - 2B, New Mexico State

Gonzales’ comps match Martin’s perfectly for the first three then diverge. You might be able to make the argument here that getting a player with the same tool se as Martin but getting him at 4th/5th/6th instead of 1st/2nd overall is a nice get. However, Martin hit in the SEC while Gonzales hit in the WAC, so the stats are more solid with Martin.

The Alex Bregman stands out, as he’s one of the few players on any of these comp tables that is a true star, but he gained stardom after a bit of a swing change that took his power grade up a few spots.

Emerson Hancock - RHP, Georgia

Really weird list. The top three guys were acquired by their respective teams as teenagers and not as a polished college guy like Hancock.

Alvarez was loved by the scouting community as a freak of nature who possessed amazing raw stuff with still good projection on it with command. As usual, the injury bug bit him like many pitchers before and he’s been just completely MIA over the years.

Whitley had gaudy numbers in the minors but has been stalled recently with both a shoulder injury and a 50-game suspension for violation of the leagues drug policy. This is a good fit in the sense that Whitley and Hancock are well rounded, but here is hoping for a smoother path to the majors for Emerson.

Zac Veen - OF, Spruce Creek HS (FL)


I mean, other than Doryss Paulino at #2 there (who was a decent prospect in his own right) this list is pretty dang good.

Kyle Tucker

Brendan Rodgers

Juan Soto

Jesus Sanchez

Ron Acuna

Bo Bichette

Carter Kieboom

A veritable who’s who of well hyped teenage prospects. Of course, the grade cement on teenagers isn’t quite as dry and that’s even more so for prep amateurs, but the grades given to Veen show the exact type of prospect he could be.

Max Meyer - LHP, Minnesota

Pretty good list of college guys with great secondary pitches (Rodon, Puk, JBB, Manoah, Beck) but also I think all of them other than Manoah have had significant injuries (which can be said of most pitchers to be fair).

Reid Detmers - LHP, Louisville

Austin Hendrick - OF, West Allegheny HS (PA)

Heston Kjerstad - OF, Arkansas

Garrett Mitchell - OF, UCLA

Woah, a Lou Bob comp right off the bat? Yeah, that’s pretty heavy for any prospect but it’s also an indication of Mitchell’s athleticism, even if he isn’t built like a Greek god like Robert.

Jared Kelley - RHP, Refugio HS (TX)

Mick Abel - RHP, Jesuit HS (OR)

Patrick Bailey - C, North Carolina State

Nick Bitsko - RHP, Central Bucks East HS (PA)