Success rates for prospects based on walk and strikeout rates: the summary

Introduction

This is the third and final time I will look at historical walk and strikeout rates for prospects. If you followed my previous installments, much of this will look familiar to you; however, these results are more complex and different. For those who are new, the basic premise is this: how likely is it that an offensive prospect succeeds in the major leagues based only on his minor league walk and strikeout rates?

Previous Installments

Success rates

Rookie | Short-A | Single-A | Advanced-A | Double-A | Triple-A

Correlation posts

Rookie and Short-A | Single-A | Advanced-A | Double-A | Triple-A

Method

First, I compiled the minor league numbers for all Baseball America top 100 offensive prospects from 1990 to 2007. I stopped at 2007 to allow enough time for the player to achieve MLB success. I only included top 100 prospects to add in a form of scouting to the picture. Stats and scouting should work hand-in-hand and an analysis similar to this can help augment a scout’s evaluation of talent.

Next, I compared each prospect’s walk and strikeout rate to the league average that year, creating BB+ and K+ metrics. Finally, I compared the walk and strikeout rates at various ages and levels of prospects in the minor leagues to their career MLB FanGraphs Batting runs. Batting runs are calculated using wOBA linear weights and adjusting for park effects. Basically this gives us the total runs above average that the player produced on offense, after adjusting for park.

In order to put players into the low, average, and high categories for BBs and Ks, I use a 15% variation from 100 BB+ or K+. This means that 85-115 marks average for each, while players below 85 are "Low" and players above 115 are "High." Since this analysis relies on bins, I allow for a 5% variation on the cutoffs. For instance, if a player has an 83 BB+ (78-88), I look at the historical percentages for both low and average walk rates.

Prospects are required to have 500 career minor league PAs to qualify in this analysis.

The following table is an estimate of where these cutoffs actually lie in terms of BB% and K% values.

	BB%	K%
Low	7.7%	15.4%
High	10.5%	20.8%

A player with at least 0.01 batting runs per plate appearance in 1500 career plate appearances is tagged "Productive," while players with negative batting runs or fewer than 1500 career PAs are "Busts." It is important to note that I am only interested in hitting ability. This is how Edgar Renteria ends up in the "Bust" category. He had a great career, accumulating 35.7 fWAR; however, his batting was worth -52.3 runs.

Results

Here are the historical results for prospects over their career, split by BB% and K%.

Over a player's entire minor league career, the best approach involves high walk and low strikeout rates. However, a lot of both or not many of either are kind of okay too. Where a player really gets in trouble is when he starts striking out without the ability to take a walk. Then he turns into a one true outcome player, where that outcome is not getting on base. That will never be the new market inefficiency.

Prospects in 2013

How do the 2013 preseason consensus top 190 prospects and select draft picks that qualify stack up in this analysis?

Name	Team	Rank	BB+	SO+	Prod%	Avg%	Bust%
Wil Myers	Rays	4	139	108	39%	15%	46%
Corey Seager	Dodgers	96	122	99	39%	15%	46%
Joc Pederson	Dodgers	121	134	95	39%	15%	46%
Michael Taylor	Nationals	6th	124	91	39%	15%	46%
Rio Ruiz	Astros	4th	121	102	39%	15%	46%
Byron Buxton	Twins	17	142	98	39%	15%	46%
Aaron Hicks	Twins	62	167	105	39%	15%	46%
Delino Deshields Jr.	Astros	88	126	103	39%	15%	46%
Dan Vogelbach	Cubs	129	143	81	39%	14%	48%
Brad Miller	Mariners	136	129	83	39%	14%	48%
Marcus Semien	White Sox	6th	145	89	39%	14%	48%
Jackie Bradley	Red Sox	34	152	89	39%	14%	48%
Jesse Winker	Reds	180	154	84	39%	14%	48%
Garin Cecchini	Red Sox	133	161	82	39%	14%	48%
Chris Taylor	Mariners	5th	146	85	39%	14%	48%
Deven Marrero	Red Sox	1st	132	85	39%	14%	48%
Max Muncy	Athletics	5th	164	79	38%	13%	49%
Jurickson Profar	Rangers	1	133	71	38%	13%	49%
Tommy La Stella	Braves	8th	127	45	38%	13%	49%
Jeimer Candelario	Cubs	165	138	80	38%	13%	49%
Mookie Betts	Red Sox	5th	152	53	38%	13%	49%
Kelvin Encarnacion	Cubs	Int.	159	76	38%	13%	49%
Francisco Lindor	Indians	16	120	63	38%	13%	49%
Jace Peterson	Padres	1st	140	66	38%	13%	49%
Billy Burns	Nationals	32nd	147	64	38%	13%	49%
Kyle Parker	Rockies	152	116	109	33%	13%	55%
Darin Ruf	Phillies	20th	114	100	33%	13%	55%
Xander Bogaerts	Red Sox	9	113	103	33%	13%	55%
Tyler Austin	Yankees	82	117	106	33%	13%	55%
Christian Yelich	Marlins	11	117	104	33%	13%	55%
Nick Franklin	Mariners	55	111	98	33%	13%	55%
Rosell Herrera	Rockies	Int.	110	97	33%	13%	55%
Max Kepler	Twins	142	114	89	32%	14%	54%
Hak-Ju Lee	Rays	76	111	88	32%	14%	54%
Josmil Pinto	Twins	Int.	113	80	31%	15%	54%
Matt Skole	Nationals	188	192	113	30%	13%	58%
Michael Choice	Athletics	111	123	117	30%	13%	58%
Gregory Bird	Yankees	5th	205	117	30%	13%	58%
Addison Russell	Athletics	33	126	116	30%	13%	58%
Jonathan Singleton	Astros	29	168	114	30%	13%	58%
Brian Goodwin	Nationals	58	147	111	30%	13%	58%
Michael Ohlman	Orioles	11th	134	111	30%	13%	58%
Mac Williamson	Giants	3rd	90	107	27%	10%	63%
Jedd Gyorko	Padres	49	108	90	27%	10%	63%
Oswaldo Arcia	Twins	61	91	99	27%	10%	63%
Josh Bell	Pirates	123	105	97	27%	10%	63%
Nick Castellanos	Tigers	25	90	104	27%	10%	63%
Carlos Correa	Astros	22	106	94	27%	10%	63%
Drew Vettleson	Rays	166	100	94	27%	10%	63%
Cheslor Cuthbert	Royals	169	96	90	27%	10%	63%
Reymond Fuentes	Padres	1st	98	105	27%	10%	63%
Roman Quinn	Phillies	164	103	105	27%	10%	63%
Billy Hamilton	Reds	23	109	102	27%	10%	63%
Jonathan Schoop	Orioles	93	95	82	26%	14%	61%
Alen Hanson	Pirates	52	99	89	26%	14%	61%
Jacob Realmuto	Marlins	146	93	85	26%	14%	61%
Blake Swihart	Red Sox	140	95	84	26%	14%	61%
Travis Jankowski	Padres	1st	93	88	26%	14%	61%
Devon Travis	Tigers	13th	102	55	24%	17%	59%
J.R. Murphy	Yankees	2nd	99	79	24%	17%	59%
Kevin Plawecki	Mets	1st	99	51	24%	17%	59%
Gregory Polanco	Pirates	54	100	78	24%	17%	59%
Kolten Wong	Cardinals	65	92	65	24%	17%	59%
Jorge Polanco	Twins	Int.	98	58	24%	17%	59%
Carlos Rodriguez	Orioles	Int.	105	28	24%	17%	59%
Travis D'Arnaud	Mets	12	87	91	23%	11%	67%
Joey Terdoslavich	Braves	6th	86	98	23%	11%	67%
Cody Asche	Phillies	4th	84	95	23%	11%	67%
Jorge Bonifacio	Royals	172	88	106	23%	11%	67%
Arismendy Alcantara	Cubs	Int.	80	103	23%	11%	67%
Roman Hernandez	Royals	Int.	82	107	23%	11%	67%
Austin Hedges	Padres	50	88	82	23%	13%	65%
Eddie Rosario	Twins	119	85	88	23%	13%	65%
Oscar Taveras	Cardinals	2	85	67	22%	15%	63%
Stephen Piscotty	Cardinals	1st	89	51	22%	15%	63%
Raimel Tapia	Rockies	Int.	83	65	22%	15%	63%
Jose Ramirez	Indians	Int.	82	44	22%	15%	63%
Nolan Arenado	Rockies	53	77	52	20%	12%	67%
Maikel Franco	Phillies	141	76	75	20%	12%	67%
Adonis Garcia	Yankees	Int.	51	67	20%	12%	67%
Wilmer Flores	Mets	149	65	66	20%	12%	67%
Taylor Lindsey	Angels	1st	69	72	20%	12%	67%
Rougned Odor	Rangers	176	64	76	20%	12%	67%
Kevin Pillar	Blue Jays	32nd	67	68	20%	12%	67%
Rob Brantly	Marlins	181	74	61	20%	12%	67%
Hector Roa	Astros	Int.	50	78	20%	12%	67%
Mason Williams	Yankees	40	77	70	20%	12%	67%
Alex Yarbrough	Angels	4th	47	74	20%	12%	67%
Christian Bethancourt	Braves	117	50	80	20%	12%	67%
Shawon Dunston	Cubs	11th	23	70	20%	12%	67%
Didi Gregorius	Diamondbacks	113	71	63	20%	12%	67%
Luis Hernandez	Diamondbacks	Int.	63	66	20%	12%	67%
Luis Sardinas	Rangers	114	75	68	20%	12%	67%
Jose Iglesias	Red Sox	157	69	76	20%	12%	67%
Jose Peraza	Braves	Int.	71	59	20%	12%	67%
Joey Gallo	Rangers	132	154	176	20%	10%	70%
Miguel Sano	Twins	15	134	136	20%	10%	70%
George Springer	Astros	46	141	135	20%	10%	70%
Mike Olt	Cubs	27	161	134	20%	10%	70%
Bubba Starling	Royals	56	126	138	20%	10%	70%
Brett Jackson	Cubs	155	136	141	20%	10%	70%
Nomar Mazara	Rangers	Int.	123	137	20%	10%	70%
Matt Adams	Cardinals	184	78	87	20%	12%	69%
Stefen Romero	Mariners	186	70	83	20%	12%	69%
Brandon Drury	Diamondbacks	13th	60	83	20%	12%	69%
Dorssys Paulino	Indians	90	71	90	20%	12%	69%
Gary Brown	Giants	103	75	84	20%	12%	69%
Adeiny Hechavarria	Marlins	149	74	85	20%	12%	69%
Carlos Sanchez	White Sox	127	77	82	20%	12%	69%
Carlos Tocci	Phillies	Int.	56	86	20%	12%	69%
Randal Grichuk	Angels	1st	50	99	19%	11%	70%
Chris Owings	Diamondbacks	120	38	107	19%	11%	70%
Jake Marisnick	Marlins	63	79	98	19%	11%	70%
Avisail Garcia	White Sox	116	47	107	19%	11%	70%
Gary Sanchez	Yankees	35	92	113	19%	6%	75%
Richie Shaffer	Rays	184	90	111	19%	6%	75%
Kaleb Cowart	Angels	48	100	111	19%	6%	75%
Edward Salcedo	Braves	181	81	114	17%	7%	77%
Aaron Altherr	Phillies	9th	80	113	17%	7%	77%
Patrick Kivlehan	Mariners	4th	82	118	17%	7%	77%
Domingo Santana	Astros	Int.	115	155	16%	6%	79%
Trayce Thompson	White Sox	145	114	141	16%	6%	79%
Trevor Story	Rockies	59	114	134	16%	6%	79%
Patrick Wisdom	Cardinals	173	116	124	16%	6%	79%
Slade Heathcott	Yankees	85	110	129	16%	6%	79%
D.J. Davis	Blue Jays	138	115	142	16%	6%	79%
Elier Hernandez	Royals	Int.	62	112	14%	8%	78%
Mike Zunino	Mariners	20	102	121	11%	2%	87%
Lewis Brinson	Rangers	108	102	176	11%	2%	87%
Max Stassi	Astros	4th	92	124	11%	2%	87%
Victor Roache	Brewers	178	101	135	11%	2%	87%
Matt Davidson	Diamondbacks	81	108	125	11%	2%	87%
Jonathan Villar	Astros	189	103	130	11%	2%	87%
Marcell Ozuna	Marlins	115	88	121	10%	4%	87%
Robert Hefflinger	Braves	7th	88	139	10%	4%	87%
Julio Morban	Mariners	Int.	80	136	10%	4%	87%
Yasiel Balaguert	Cubs	Int.	88	135	10%	4%	87%
Javier Baez	Cubs	18	65	123	9%	5%	86%
Adam Walker	Twins	3rd	71	121	9%	5%	86%
Courtney Hawkins	White Sox	71	68	164	9%	5%	86%
Jorge Alfaro	Rangers	104	61	142	9%	5%	86%
Nick Williams	Rangers	2nd	56	130	9%	5%	86%
Yorman Rodriguez	Reds	Int.	76	134	9%	5%	86%
Adalberto Mondesi	Royals	105	79	122	9%	5%	86%

That is quite a few names and I can't cover the placement of all of them. However, a few stick out: George Springer's approach has been the cause of much concern. However, his high walk rate saves him, and this needs to be more widely disseminated. At the bottom of the list are three very interesting prospects: Javier Baez, Jorge Alfaro, and Raul Mondesi. Each are highly regarded and for many a good reason. Their current approach is not one of them, though.

I talked at some length about Baez in the Advanced-A version of this series. He is a unique prospect, possessing ridiculous power potential from the shortstop position. That combination of power and position lead him to kind of "break" this system. However, I am still leery about his inability to take a walk.

Alfaro is a catching prospect and as such, I am willing to cut him some slack, since catchers are a completely different animal offensively. Much less is expected of them and they may mature at a slower rate. Speaking of maturing, Mondesi needs to do much of that, and 2014 will be his age-18 season. His walk rate dropped quite a bit this past year, and he will need to work on that, but he still has plenty of time to do so.

Summary

What did we learn since starting this series four months ago? Extreme rates at lower levels are actually okay. Don't worry about a prospect's high strikeouts and low walks until he gets into the upper levels. Age is a definite determining factor, even among prospects at the same level. Much more is expected from a 22-year old at Double-A than a 21-year old.

As is the traditionally held value, success in Double-A is an extremely important step for a prospect. A player really needs to get through there before his age-22 season, or else he is fighting against history.

It's generally bad for a prospect to not walk a lot, but there are certain ages and strikeout levels where that is not such a terrible sign, particularly if the player also doesn't strike out a lot. High strikeout totals can be perfectly acceptable at lower levels and at upper levels with an equally high amount of walks. A high walk rate is the best determining factor in a player's approach for his chances at becoming a productive hitter.

Conclusion

One main point of contention in this series is that it ignores power. Players who can hit the ball out of the park with regularity have an upper hand, even with a less than desirable approach. Initially, I ignored power because so many variables go into minor league power numbers. However, with the help of the team here at Beyond the Box Score, my next series will go more in-depth on how power develops and how it correlates to major league success.

. . .

Statistics courtesy of Fangraphs and Baseball Prospectus.

Chris St. John is a writer at Beyond The Box Score. You can follow him on Twitter at @stealofhome.