Get a good pitch to hit is a ubiquitous tenet of hitting in player development systems across baseball. A walk represents success because it moves the chain along without costing an out, but the walk is an outcome of waiting for a good pitch to hit. A hitter with a tiny walk rate (particularly coupled with a high strikeout rate) in the minor leagues can be a sign of a hitter with pitch recognition issues.

Hitters can get by in the lower levels of the minor leagues with great tools and a terrible approach, but more advanced pitchers in Triple-A and the majors will pick them apart with superior stuff and superior ability to locate their pitches. (Conversely, polished hitters who rely on a selective approach in the lower minors but lack major league-caliber tools can also see their production dissipate as they progress, but for today we’ll just focus on the impatient.)

Can an impatient approach work for some players? Sure, but it’s rare to see and usually is reserved for the freakishly talented who have the ability to barrel up balls at an elite rate and have above-average power. So which hitters saw their prospect status take a hit because of their free-swinging ways? These four fit the bill (note that UIBB stands for unintentional walks, while I have removed intentional walks from each player’s plate appearances count):

PLAYER          	LEVEL	PA	UIBB	SO	UIBB%	K%
Engel Beltre, TEX    	HiA	443	16	77	3.6%	17.4%
J.P. Arencibia, TOR  	AAA	500	26	114	5.2%	22.8%
Welington Castillo, CHC	AA	336	13	71	3.9%	21.1%
Greg Halman, SEA     	AA	503	28	183	5.6%	36.4%

All four players ranked among the top 10 prospects in their organizations, with Halman and Arencibia cracking the Top 100 Prospects list coming into the year. Should we have seen it coming? Let’s look at what they did last year.  

PLAYER          	LEVEL	PA	UIBB	SO	UIBB%	K%
Engel Beltre, TEX    	LoA	596	13	105	2.2%	17.6%
J.P. Arencibia, TOR     HiA/AA	535	16	101	3.0%	18.9%
Welington Castillo, CHC	HiA/AA	345	16	73	4.6%	21.2%
Greg Halman, SEA     	HiA/AA	536	29	142	5.4%	26.5%

Beltre and Halman spent a bit of time in the Arizona League (Beltre also played four games in Double-A), but I’m leaving those scattered PAs out for now.

Arencibia hit 27 home runs last year and hit another 22 in Triple-A Las Vegas’ bandbox, but still hit just .236/.284/.444. A .284 OBP in the Pacific Coast League for a 23-year-old isn’t good enough to play anywhere in the big leagues, even as a catcher.

It’s too early to completely write off Beltre, but the 19-year-old Dominican outfielder will need a dramatic turnaround in his approach to resurrect his prospect stock. But he didn’t hit much last year and followed that up by showing little improvement in the high Class A California League, where he hit .227/.281/.317.

Castillo has outstanding arm strength, but he’s a free-swinger who hit just .232/.275/.386 in 95 games with Double-A Tennessee. With his catch-and-throw skills behind the plate, Castillo could carve out a big league role, but his plate disicpline looks like it will limit him.

Halman still has excellent raw power—you have to to finish the season with just 96 hits but have 25 homers—but his weaknesses have become exposed ever since the Arizona Fall League last year. Even though he put up solid numbers on a superficial level between high Class A High Desert and Double-A West Tenn last year, the warning signs at the time—his long swing, inability to recognize offspeed pitches and below-average plate coverage—were all there, and he’s only gone backwards since then.