In the typical 5x5 Roto league scheme, all pitchers are evaluated on the basis of ERA, WHIP and strikeouts. Relievers collect saves (and the occasional win) while starters garner victories (and/or quality starts). Points leagues often do incorporate other statistical categories, such as innings pitched, hits and walks allowed (all three of which are, admittedly, part of the WHIP stat) and potentially more esoteric categories, such as complete games/shutouts (a pair of true rarities these days) as well as negative point categories such as losses, blown saves, earned runs (again covered by ERA).

Whether evaluating counting stats or ratios, these methods of evaluating those who toss the baseball for a living need not the serve as the statistical be all, end all in terms of rating their abilities. Baseball, being a sport that has long been the source of extensive statistical analysis, continues to develop other and different means of appraising performance on the mound. Whether these new and developing statistical assessors are better means of determining which arms you want to populate your roster with at the draft or during waiver/free agency time, that remains to be determined. In the meantime, let’s take a gander at the various underlying statistical measuring tools that the sabermetric minds have created for our use in the ongoing quest to win our leagues.

One point to note, you will have to dig around to locate some (not all) of the following statistical values, especially since the predictive stats are not generally reported in the player projections or season stats for pitchers. The simple fact that the data is not readily available, however, can certainly provide those with the desire to research and investigate an advantage over their competition in their search of fantasy trophies.

For convenience purposes, the metrics will be grouped in four categories: Strikeouts, Walks, Runs Allowed/Prevented, and Pitching Efficiency. We shall explore the land of balls and strikes first, then delve into the more esoteric predictive categories.

Walks (BB/9, BB%)

No matter how you slice it, walks are a negative aspect in a pitcher’s performance on the hill. Handing out free passes inflates the WHIP, increasing the traffic on the basepaths while forcing the batter to strike the ball and put it where the fielders ain’t (shout out to Willie Keeler), and in unfortunate cases, leads to earned runs being debited against the pitcher’s stat line. It stands to reason, therefore, that pitchers that can avoid throwing four balls to a batter before generating another response from the opponent wielding a bat at the plate, will fare better overall.

Both BB/9, measuring the number of walks a pitcher would allow if he threw nine innings (quite the rarity these days) and BB%, which measures the frequency that a pitcher allows a free pass to an opposing batter, exist to demonstrate in terms of numbers what sort of control (or lack thereof) a pitcher possesses, as opposed to dominance and command which are measured by the next analytic category, the strikeout. The more walks allowed, the less control a pitcher shows over his ability to throw pitches for strikes, and to control how a batter’s plate appearance progresses. The average among major league pitchers in terms of these stat measuring sticks is 2.9 BB/9 and 7.7% BB%. An excellent control pitcher will put up sub 2.00 BB/9 rate and a percentage of walks allowed south of 5.5%.

One consideration when evaluating based on BB% basis, if a pitcher accumulates excellent strikeout numbers (i.e. his K% is in the elite range), he can have an inflated walk rate and still provide excellent value. Those arms that do not rack up the K’s, though, are the ones you will want to pay close attention to with regard to these two metrics.

Strikeouts (K/9, K%, K/BB, Swinging Strike%)

Collecting strikeouts is a skill prized among all pitchers, whether they start the game or come on in relief. There are four essential results in an at-bat: strikeout, walk, home run or ball in play (sure, a hitter can be awarded a base by being struck by the pitch, but that is not a frequent event for most hurlers). The pitcher is in control of the first three events primarily, while he has to rely on his defense to determine what occurs when the ball is struck. The strikeout is obviously the preferred outcome for the pitcher of the three events he has under his dominion, as the batter returns to the dugout without obtaining the opportunity to score a run or drive in any “ducks on the pond.”

A great pitcher will rack up a strikeout per inning pitched, or a 9.00 K/9 rate over his innings pitched. The best relievers will exceed 12.0 K/9 due to their ability to rear back and bring it, although certain starters (Gerrit Cole , Max Scherzer , Robbie Ray , Tyler Glasnow , Chris Sale to name the best) also excel at missing bats and racking up the whiffs. Command in a pitcher’s performance is measured in the K/BB rate he provides, and the best arms will have a 3.00+ K/BB ratio to provide their fantasy owners. To have success in the command department, numerous strikeouts are not a requirement, but an effective arm will need to significantly lower the number of walks to offset the absence of swings (strikes) that do not put the ball in play.

Swinging Strike% measures the times a hitter swings at a pitch and misses divided by the total number of pitches faced. It is evident that a pitcher who can fool a hitter and miss his bat is more likely to be successful toeing the rubber than someone who allows batters to put the ball in play continually. League average hovers around 9.5-10% in this metric, so finding an ace that misses the bat with more than a tenth of offerings is one to target. Those aces that put up high K/9 rates are successful at this, obviously, but a low strikeout producer will benefit from fooling opposing offenses if he can find success making the hitter contact the pitcher’s pitch, as is the case with those pitchers that generate more than an average amount of groundballs or popups.

Because K’s are one of the five stat categories in standard 5x5 roto leagues, and are a positive counting stat in points leagues, it behooves the fantasy owner to target those aces that rack up huge strikeout numbers. Looking to the percentage metrics of K/9, K% and K/BB helps to identify those starters and relievers that will contribute to success at the end of the season. A good producer of swinging strikes may not rack up the K’s, but his ratio stats should be benefitted by the failure of opponents to make contact.

Runs allowed or prevented (FIP, xFIP, BABIP, SIERA)

FIP is the acronym for Fielding Independent Pitching, which attempts to measure a pitcher’s performance assuming he is backed by an average defense, not the particular set of fielders that play around him on the field. It takes into account the number of homers, hit by pitch, walks and strikeouts a pitcher accumulates, those being results attributed to his efforts on the bump, and stripping away the effect of his teammates’ fielding efforts, while measuring his actual performance against league average. The goal in calculating a pitcher’s FIP is to eliminate luck, sequencing (the timing of events which can result in huge variance in terms of runs scored) and team defensive skill or lack thereof.

xFIP expands on the FIP idea by substituting the actual home run rate for any particular pitcher with an additional calculation taking into account league average home run rate on fly balls, in conjunction with the hurler’s own fly ball rate. This change is meant to determine just how many crash-bombs a particular SP or RP should allow, all things adjusting to the league norm. xFIP, then, in addition to peeling away the influence of defense, luck and timing/sequencing from a pitcher’s performance, also attempts to strip away the randomness associated with the number of home runs a pitcher will allow over time.

Both FIP and xFIP are better employed as predictive metrics, as their short-term forecasting tendency can be wildly fluctuating. In other words, these stats need larger sample sizes to be effectively extrapolative, as small inning trials are far less reliable than a half or better yet, a full season’s set of numbers for an arm on your fantasy staff. Also, neither metric is league or park adjusted, working with MLB averages instead. Pitchers who have a “pitchers’ park” as their home stadium will consistently produce lower FIP’s, all other things being equal (which they never are, but certain general groupings of like-skilled players can be compared with effective results, naturally). Of course, pitchers can outperform their FIP (or conversely, underperform their FIP) if they are extraordinarily successful at limiting homers while generating more than their “fair share” of fly balls (fly balls going for hits less often than ground balls and line drives) or exceeding average rates of holding runners on base, but these arms are the exception.

BABIP (batting average on balls in play) measures how often a ball hit by a batter in play goes for a hit of whatever sort. A “ball in play” is defined as an instance where a hitter’s plate appearance ends in a result other than a walk, strikeout, hit by pitch, sacrifice bunt, catcher interference or home run. On average, approximately 30% of all balls in play land safely for hits. Be advised, however, that three factors largely influence this statistic, those being luck, defense and talent level. BABIP is used to assess both hitters and pitchers, with both sets of players’ average rates settling in at .300. In the case of hurlers, if the BABIP is below the league average, he could benefit from pitching in front of a superior defense, exhibit exceptional talent on the bump, or be favored with marvelous good luck. Or benefit from all three of those factors, or two of the three. Conversely, an inflated BABIP generally tends to indicate an unlucky pitcher, in general terms or having to pitch with a porous defense backing him up. Although some pitchers consistently have low or high BABIP ratios over their careers, frequently a pitcher with a bloated or severely depressed ratio will eventually see his BABIP trend toward the league norm. Be advised that it takes a significant amount of pitching performance to establish a pitcher’s baseline BABIP, generally three seasons of action, so momentary fluctuations in the ratio are not necessarily good indicators that a pitcher is regressing either negatively or positively. Coupled with the fact that most pitcher’s BABIP ratios fall in the range of .290-.310, this ratio stat is poorly suited for use as a fantasy stat category. Not that it is not useful in determining a player’s projected future results, especially since once the ball leaves a hitter’s bat, it is almost entirely outside of the pitcher’s control, and those pitchers with extreme BABIP ratios, unless saddled with a truly horrific defense, will likely see their performance on balls in play return to league normal levels over time.

Another predictive metric exists for us stat heads to ponder and consider: SIERA. The acronym stands for Skill-Interactive ERA, and in addition to exploring the role of the pitcher-influenced events during a mound-appearance, namely strikeouts, walks, batters struck by pitches and home runs, it also considers how balls in play (groundballs and flyballs primarily) have an effect on a pitcher’s success. It factors in a great value for high strikeout pitchers, while also recognizing that the ability to limit walks is a skill that benefits mound aces. While certainly an ERA estimation tool, it should be noted that SIERA works best as predictive metric that is backward looking as opposed to forward thinking. Still, because of the intention to evaluate the how and why of pitching, it has the potential to be both accurate and predictive in its approach to statistically probe the extraordinarily process of pitching a baseball. SIERA has the additional benefit of taking into account ballpark variance and the effect a particular stadium will have on a pitcher’s performance on the hill.

Pitching Efficiency (GB/FB/LD%, GB/FB%, HR/FB%, LOB%, Barrel%, Hard Hit %)

An efficient pitcher will limit the times a hitter puts the ball in play, while working to keep him off the bases by fooling him with movement on his pitches, location of the baseball or guile and knowledge of a hitter’s weaknesses and/or tendencies. It is inevitable, however, that opposing offenses will not all swing and miss at every offering a pitcher tosses, and therefore, stats have been recorded that are helpful in determining which hurlers have the best chances of succeeding on a regular basis. Regular success is what we seek in our fantasy rotations and bullpens, and success is certainly the desired goal.

Line drives are traditionally the type of hit a pitcher wants to avoid. Groundballs frequently can be run down by infielders, or are hit directly to a shifted defender, and flyballs are much more likely to end up in a fielder’s glove than those frozen ropes that frequently fall in safely over the head of the closest infielder and in front of the outfielders, or in between those defenders patrolling the outer reaches of the field. All things being equal (which they generally are not), a fly ball is more likely to result in an out than a grounder, and both the groundball and flyball are preferred over the liner. Fly balls, to be certain, lead to more extra base hits, and thus groundball-inducing pitchers are valued as their damage occurs in small cuts (singles, possibly doubles) whereas flies are deeper slashes, especially if the ball travels over the fence as a dinger. Beware of looking at LD% too quickly in a season, as it usually takes longer for the line drive percentage to stabilize for analysis purposes, perhaps half a season or more. Groundball-inducing pitchers will have a percentage of 50% or better, while a flyball pitcher will generate 40% or better rate.

Speaking of fly balls, the rate at which such batted balls leave the yard is of interest in evaluating pitchers. League average trends toward 10% over the long run. It obviously takes some time to establish a pitcher’s rate of allowing homers on the fly balls hit off his pitches, but even once that trend is clear, beware of the pitcher simply suffering through a stretch of bad luck. As with most variations from league average, it should be anticipated that over the haul the numbers will regress to the norm. A pitcher in a hitters’ park (Coors Field comes to mind) will also have a higher HR/FB rate than someone in a more spacious home field, such as Marlins Park in Miami.  It bears watching whether a specific pitcher has a skill set that results in a better than average rate of keeping the ball within the field’s confines, or suffers from a propensity to allow more than his fair share of round trippers.

The ability to strand runners is reflected in the left on base percentage stat (LOB%). Certain pitchers have a skill set that allows them to carry unusually high LOB% rates for a season, or a career. Relievers that have high K/9 rates are naturally effective at stranding baserunners, but other pitchers seem to bear down once the bases contain potential runs. Generally, if an average pitcher suddenly has a significantly improved LOB%, it is usually chalked up to his being lucky, and a regression to the mean is expected to take place. The reverse is also true, and a pitcher with an abnormally low LOB% is considered due for an uptick in (mis)fortune. Those at the high-or-low end of the range do have the potential to regress to the mean, and thus this stat has a contemporary predictive capacity, League average falls around 72%, while anything above 80% is stellar.

Barreling up the ball and hitting it hard are skills that hitters cherish, but they are detrimental to pitchers. These stats are not purely indicative of a pitcher’s success on the mound, however, as a certain amount of hard-hit balls will find their way into fielders’ mitts. But the ability to generate soft-hit efforts by the batter is favored by most pitchers. Likewise, avoiding the barrel of the hitter’s bat will assist the pitcher in limiting damage by the opposition. Barreling is defined as a well-struck ball which has a combined exit velocity and launch angle that is anticipated to result in a .500 BA and 1.300 Slugging Percentage at a minimum. The faster the velocity, the more forgiving the launch angle. Barreled balls result in extraordinarily high batting averages for hitters, and thus are extremely disfavored by those tossing the ball toward the plate. A pitcher with a Barrel% above nine percent is worrisome, but one who can limit barrels to something at five percent or less is extremely valuable. Hard hit rates have become much more available while the barrel% is scarcer on stat services, but as with most statistics, can be uncovered by the diligent fantasy researcher. 

The bulk of the analytical tools above are all more predicative than of future performance while gazing back at prior performance of the pitcher’s previous efforts on the mound, except for those that will tend to revert to the mean, or league average. But to be fair, all stats are predictions of future ability based on past performances and we are making our best guesses when drafting or adding players to our rosters. Do not rely on any one statistic to make a decision about a pitcher; instead, use the tools detailed above to compile a detailed profile of a targeted arm. A pitcher with a higher-than-average HR/FB% pitching for the Orioles but whose FIP and xFIP are a full run below their ERA, and who has a better than average K/BB ratio is someone to target, if just for spot starts on the road, for example.

Winning at fantasy is not easy and would not be nearly as rewarding if it were. Do your homework and reap the benefits. Going the extra mile can frequently result in favorable results.