Background

The Dynasty Guru updates its peak performance leaderboards weekly. View the latest update here (updated through June 13th).

The leaderboards present peak MLB wOBA for all players, minor and major leaguers. Peak MLB wOBA takes 2019 minor league wOBA and adjusts it downward to an MLB baseline (for example, a .400 wOBA in the International League is equivalent to about a .350 wOBA in the MLB). The extent of the downward adjustment depends on how hard the league is (e.g., Triple-A is harder than Single-A). This allows one to compare performances from different leagues on the same MLB scale. Peak MLB wOBA also adjusts upward for aging. Peak MLB wOBA adjustments are derived from recent research on aging and translating minor league performance (see here, here, here, here, and here.

The List

Ross Jensen and I have been updating the leaderboards weekly in this series, “Scouting the Stat Line.” In the pre-season, we presented a top 50 stats-only offensive prospects list based on Peak MLB wOBA for 2018 minor league performance. What follows is our first in-season list based on 2019 performance so far. This top 50 list isn’t meant to replace scouting or more traditional lists. It’s simply a robotic, automatic ranking that captures how 2019 minor league performance translates to future MLB performance. It’s biggest flaws are threefold: 1) it ignores pre-2019 performance; 2) it ignores scouting 3) it doesn’t adjust for BABIP luck. It should be used to complement more traditional, holistic, and in most ways superior lists–for example, see Jesse Roche’s updated top 200 list from two weeks ago. Used correctly, we think this list can help isolate certain undervalued assets in the prospecting community.

Only players with less than 130 MLB at-bats are included. Pre-2019 performance is ignored. The rankings are based on statistics through the games of June 13th. Players must have accumulated at least 140 plate appearances in 2019 to be eligible. Old-for-level players are excluded (maximum age of 23 for Triple-A, 22 for Double-A, etc.). Find a few notes below the list.

Notes:

Guys who also performed well in 2018 inspire more confidence than guys who didn’t. Of the top 25, the following guys all excelled in 2018: Yordan Alvarez, Luis Urias, Austin Riley, Wander Franco, Alejandro Kirk, Carter Kieboom, Kyle Tucker, Gavin Lux, Seth Beer, Jarren Duran, Alek Thomas, Abraham Toro, and Nolan Jones.

Alejandro Kirk has had an absolutely stellar career so far, always mashing at young ages relative to the competition–in rookie ball, Single-A, and now in High-A. I haven’t seen him on a top 100 yet, mostly for defensive reasons, which is nonetheless a bit of a head scratcher considering his offensive prowess.

These guys didn’t perform as well last year and are unlikely to sustain much of their first-half gains for the entire year: Sam Huff, Mario Feliciano, Canaan Smith, Ulrich Bojarski, Nick Longhi, Aramis Ademan. I wouldn’t treat any of them as top 150 prospects.

Heliot Ramos also struggled in 2018, but I fully buy his 2019 gains: he is super young, he was so good in 2017, and he’s a scouts’ dream. In The Dynasty Guru’s Experts League, I recently traded Trevor Bauer to prospects expert Jesse Roche for a prospect package highlighted by Nolan Gorman and Heliot Ramos.

You could pretty much say the same for Luis Robert as for Heliot Ramos, another guy I’m buying where I can (he was amazing in Cuba before struggling in very limited and injury-riddled at bats in 2017 and 2018).

Beware BABIP-inflated performances. Drew Waters’ .463 BABIP in Double-A will come down a lot–he’d drop at least 20 spots with with a more reasonable BABIP.

These numbers are league-adjusted but not park-adjusted. Players like Brendan Rodgers receive an artificial boost from hitter-friendly home parks (statcorner.com has his park-adjusted wOBA at .421 versus .442 unadjusted). Of course, he’s not a great example , practically speaking, as he’ll continue to receive this boost in the majors in Colorado.

When analyzing players on the list more in-depth, look for guys with strong raw skills rather than inflated BABIPs–especially focus on strikeout percentage, walk percentage, and isolated power. Kyle Tucker illustrates this idea well: his 10% walk rate, 22% strikeout rate, and .351 isolated power validate his spot in the rankings.