2020 MLB Draft Guide: Utilizing Walk and Strikeout Rates

If you previously read my Draft Guide article on Fantasy Baseball Points Leagues you’ll know that I value walk and strikeout percentages when evaluating players. In a points league, these metrics play a pretty big role in determining a player’s value, but these numbers do have their uses in rotisserie and head-to-head category leagues as well.

Walk Rates

To the surprise of absolutely nobody, higher walk rates for hitter’s are good, but bad for pitchers. Starting with the offensive side, a high walk rate for a hitter normally translates to great plate discipline. And it’s no surprise that you’ll find some of the best hitters in baseball at the top of the list for walk rates:

That’s the importance of walk rate in fantasy baseball. You channel you inner Brad Pitt/Billy Beane to find guys who can get on base. Walks can lead to runs and potentially steals. However, it is worth noting that out of the list above only seven players (Trout, Soto, Harper, Bellinger, Yelich, Betts, and Pham) registered double-digit steals. But every little bit counts so if you are in a league that may be doing away with batting average. If you’re entering a points league or a league substituting OBP for BA, then you’ll want to keep a close eye on the walk rates for hitters.Look at that list. It’s filled with Current and former MVP’s and solid power hitters. 15 of the players listed above hit at least 28 home runs and 14 of the players above ranked in the Top 30 in on-base percentage (OBP) in 2019. Plate discipline and walks can truly aid a player’s fantasy value. Look at Daniel Vogelbach for example. He ranked 134^th out of 135 hitters in batting average (.208) with at least 500 plate appearances. However, since he ranked fourth out of 135 hitters in walk rate, he was able to rank 71^st out of 135 with a .341 OBP. Middle-of-the-pack certainly isn’t groundbreaking, however his walk rate still put him on base enough for him to score 73 runs. Add in the 30 home runs and 76 RBI and Vogelbach turned out to be a decent addition off waivers in 2019.

Now on the other side of the ball, walks are bad. Duh, right? While higher walk rates are never good for a pitcher, they coincide with a pitcher’s walks per nine innings (BB/9). Personally, I only worry about a pitcher’s tendency to allow free passes if they tout a 3.00+ BB/9. A walk every three innings can be tolerated. And among qualifying starting pitchers last season there were 17 pitchers with at least a 3.00 BB/9:

Many of these names also appear towards the top of walk percentage as well. You’ll see some big players on this list such as Aaron Nola , Trevor Bauer , Patrick Corbin and even to a lesser extent there are still some viable fantasy players on the list. Robbie Ray certainly stands out with his walk rate where he averages almost a walk every two innings. Ray’s been an anomaly for a few seasons now, but it’s clear that while he is capable of elite strikeout numbers, his walks and home run rate (1.55 HR/9) are a big problem and make him a massive fantasy risk. And that should apply to other pitchers as well. A pitcher with a slightly higher walk rate can still be rostered if they rack up strikeouts and keep the ball in the park. Luis Castillo and Patrick Corbin are great at generating strikeouts while allowing almost one home run per nine innings. In 2020, that’s a decent enough rate given the spike in power we saw in 2019.

Truth be told, walk rates apply more towards relief pitchers, and rightfully so. These guys are only brought in for short work, maybe an inning or two. You can’t afford to have these guys allowing free passes left and right. Here’s a pretty thorough look at the 20 worst relief pitchers in terms of BB/9:

As you can see, none of these guys were season-long closers. Blake Treinen , Brandon Workman , and José Leclerc are the only players listed to log double-digit saves. Most of the players in the table above are setup men, but some players did get the opportunity to earn some saves. But the free passes clearly don’t translate to a healthy ERA for these pitchers. 14 pitchers have an ERA over 4.00 and even a guy like Adam Ottavino benefitted from some good luck and a higher strikeout rate because his FIP indicates his 1.90 ERA could’ve been much worse. Elite closers are hard to come by, but typically they are better are keeping the walks to a minimum. But as we can see from the table above, walks can be detrimental to a reliever’s performance if too many runs are scored.

Strikeout Rates

It’s never fun to watch your fantasy hitters strikeout. However, that’s just the nature of the game sometimes. Players that swing for the fences will miss more than they’ll actually launch one over the wall. There were 28 players in 2019 that had a strikeout rate of at least 25% and they all hit at least 20 home runs. 19 of those players hit at least 28 home runs. So, there is a correlation among power hitters that power does come with its downside of strikeouts. Even if you refer to the first table in this article (top 20 walk rates among hitters), only one player (Alex Bregman ) had a higher walk rate than strikeout rate. Carlos Santana ’s walk rate did match his strikeout rate and Mookie Betts came close with a 13.7% walk rate and a 14.3% walk rate. Even the most patient hitters in the league struck out more than they walked. Michael Brantley was a valuable fantasy asset last season with 22 home runs, 88 runs, and 90 RBI. He walked 8.0% of the time and struck out 10.4% of the time. So, among the 135 qualified hitters, Bregman was the only player to walk more than he struck out.  

Now back to the opening part of this paragraph, a fantasy baseball player can return value even with a higher strikeout rate. Joey Gallo has touted a strikeout rate of at least 35% in three straight seasons. In 2017 and 2018, he hit 40+ home runs in each season and if he didn’t miss half the season last year, he probably would have done it again as he finished with 22 dingers in 70 games with, once again, an extremely high walk rate (38.4%).

Now in a points league, a vast discrepancy between walk rate and strikeout rate can be fairly detrimental to your team if they aren’t returning significant value. Domingo Santana had the worst walk rate (32.3%) among players with 500 plate appearances but walked in 9.9% of his plate appearances. He still yielded 21 home runs, 63 runs scored, and 69 RBI. Those are decent numbers but could be better if he could even drop his K-rate to 25%. So, strikeouts for hitters aren’t a death nail. Players swinging a heavier stick are prone to strikeouts, but they can still contribute in the counting categories.

Naturally, strikeouts are what we aim for with pitchers. Strikeout rates carry more weight for pitchers than they do hitters. Since hitters can compensate in other categories, a pitcher with a low strikeout rate better have a damn good BABIP to opposing hitters if they’re primarily relying on ground outs and pop outs. Strikeouts can play a huge role in your fantasy baseball league depending on the value they get or the number of categories there are incorporating strikeouts in some capacity. Accumulating strikeouts, strikeouts per nine innings (K/9), strikeout-to-walk ratio (K:BB), etc. are all popular among category leagues. Sure, there are the elite pitchers in baseball that average over 10.00 K/9, but if you can find arms that average a strikeout per inning (9.00 K/9) or slightly less, then that is a good bar as well.

And you don’t need to examine just strikeouts but look at swinging strike rate as well. Swinging strike rate is the most important factor to look at when evaluating pitchers. In-season it’s a useful metric when looking to see if a player’s increase in strikeouts is legitimate. Typically, if a pitcher is garnering more swinging strikes then he’s showcasing not just solid control, but potentially increased speed in his fastball, better velocity separation in his changeup, or better movement with his breaking pitches.

Strikeouts and walks can be viewed as the yin and yang of baseball for pitchers and hitters. Yet they aid in different ways depending on what side you play on. These two rates are two important metrics one can use when analyzing a player’s profile and they’re both highly valuable tools to use during the season when evaluating whether a player’s start or streak is legitimate or fluky. If looking for thorough strikeout and walk analytics, Fangraphs is a great site that offers in depth analysis on swings, misses, whiffs, swings out of the strike zone, contact, etc. Those typically apply to hitters, but they also offer insight into swing percentages as well as the value of a pitcher’s repertoire. There’s plenty of analysis beneath the surface of strikeouts and walks and these metrics should be on your radar when evaluating the talent you want on your fantasy baseball team.