Do Lefty Pitchers Have An Benefit?

As a lefty getting into 9U Child-Pitch, coaches made certain at a younger age that I knew find out how to pitch. Lefty baseball gamers from all around the globe will doubtless inform an identical story. It’s ingrained within the fiber of most little league coaches, Main League Baseball followers, and even professionals… that lefty pitchers typically have a bonus when stepping onto the mound versus righty pitchers. It stands as one other scroll within the massive library of dogmatic baseball recommendation, with managers of all kinds utilizing this data consciously or subconsciously to affect their selections. And whereas typically this dogmatic recommendation could be statistically true, the essential error is available in taking the information at face worth. Is there any precise reality to this lore? There have been a number of appears to be like at an identical query, however the level of this text is to supply a extra up-to-date have a look at the query, in addition to a greater diversity of surrounding factors. In acknowledging all of those components, one can digest the problem as a complete.

The Preface: Platoon Benefit

Earlier than diving into this, there’s a essential premise that must be re-established – the platoon benefit does exist. Most notably confirmed in The E book: Enjoying the Percentages in Baseball, it needs to be recognized that lefty pitchers have a bonus towards lefty hitters, and righty pitchers have a bonus towards righty hitters. When the pitcher faces the batter of the alternative handedness, the batter now has the comparative edge. And whereas this has been confirmed time and again in different items, it appears hypocritical to not present the essential proof of the premise on this piece. Utilizing knowledge from 2012-2022 (excluding 2020), these are the wOBAs for every hitter and pitcher handedness matchup weighed by the variety of video games in every season:

All Visuals by Kane Schwarz.

As is obvious within the desk, Proper-Handed Pitchers did about 15 factors higher towards the same-handed hitter, and Left-Handed Pitchers did about 32 factors higher than the same-handed hitter. With this knowledge being over a good pattern of years (10) and nonetheless being considerably sizeable, it is vitally secure to once more conclude that Tom Tango was proper. With that etched in stone, the potential benefit or disadvantages of Lefties might be a lot simpler to show.

Handedness Pitcher Worth As A Entire

Most likely probably the most fundamental look of the entire article, exhibiting the general worth of Lefties and Righties as a complete, no matter matchup, may give a great sense of if one noticeably has a bigger benefit. As a complete over the pattern, Lefties’ wOBA towards is 0.315471, whereas Righties’ wOBA towards is 0.314833. Rounded to the closest third decimal place as wOBA typically is calculated, they each stand equal at 0.315. Solely the deeper look showcases the 0.638 factors (0.000638) distinction. Evidently, this distinction is negligible and reveals no signal of a certain-handed pitcher having the benefit over the opposite. The same story is informed with OPS towards, as each side averaged 0.727. With regard to their capability to get outs themselves whereas limiting free passes (Ok% – (BB% + HBP%)), LHP’s whole batter confronted common was 12.2%, whereas RHP’s was 12.3%. This distinction is once more very minute.

As a complete, neither hand of pitcher doesn’t have a bonus over the opposite primarily based on the result. However what about on a year-to-year foundation? Was there any given yr the place one hand completely outshined the opposite? Right here is the wOBA of every hand, by yr.

Just one yr stands out on the graph – 2019. In 2019, Lefty pitchers allowed 6 extra factors of wOBA in comparison with Righties. Within the grand scheme of baseball, these 6 factors are very minute to be the max distinction in a given yr over a big pattern of seasons. Therefore, that is nonetheless not sufficient to show utilizing one can be extra advantageous.

Handedness Pitcher Worth By the Matchups

Whereas touched on within the preface, a extra in-depth have a look at the platoon’s benefit and detriment for certain-handed pitchers will help analyze this lore extra successfully. As could be seen within the matchup desk above, same-handed matchups have a pitcher’s benefit, whereas opposite-handed matchups curl in direction of the hitter. Although the very fact of benefit stays fixed, the precise levels of those benefits are a lot totally different. Reiterating from above, Lefties did 32 factors higher towards their same-handed opponents than their opposite-handed ones (0.293/0.325). Righties did solely 15 factors higher (0.308/0.323). A 17-point distinction is a comparatively important margin, and such exploitation of matchups might add as much as plenty of runs saved over a big sufficient pattern. To place this into perspective, right here is the year-over-year platoon benefit for lefty and righty pitchers.

For this graph, a constructive platoon benefit (as proven) equals a decrease wOBA allowed. Over the whole thing of the pattern, the Lefty wOBA platoon distinction stays considerably greater, with the 2 traces not overlapping as soon as. That unfold was maximized in 2021 when LHPs have been gaining 40 factors off of the platoon in comparison with the RHPs’ 12 factors. Towards the opposite-handed batter, the 2 sides produced related numbers, with RHP/LHH averaging a 0.323 wOBA and LHP/RHH averaging a 0.325 wOBA. Provided that they’re each at a considerably equal drawback, the potential matchup exploitability of a Lefty might show some extent concerning an additional sense of worth.

Each of those factors show, to an extent, a way of additional worth for Lefty Pitchers. It showcases some extent of exploitability for which sure particular conditions make them beneficial. And whereas the combination statistics present no such distinction, the optimization of those conditions might in the end show to make Lefties extra beneficial as a complete compared to Righties. In fact, there are certain to be diminishing returns regarding this, which might be mentioned additional in one of many following sections.

Pitcher Stuff by Handedness

Whereas this level has been iterated in lots of articles, such a glance doesn’t really feel justified with out it – Lefty Pitchers don’t have pretty much as good of stuff as righties. Utilizing Savant pitch knowledge solely from the 2022 season, these charts present ample proof of that:

Throughout the common velocities, Righties have been the winners for each one of many main pitches used within the knowledge. Whereas some pitches have been by wider margins than others, main in each attainable pitch reveals that their capability to pitch at greater than lefty speeds is existent. The Spin charge story is rather less easy.

Of the 7 pitches that have been checked out, RHPs led in spin in 4 – Sliders, 4-Seams, Sinkers, and Splitters. For the primary 5 pitches proven, it’s typically good to steer in spin, as it’s barely related to elevated pitch efficiency. For the final two (Changeups and Splitters), the pitches typically thrive of their capability to have restricted spin. Even discounting these two, the Righties nonetheless maintain a slight edge of their capability to generate spin compared to Lefties. Pitch shapes add one other perspective to get a greater general view of every hand’s “stuff”.

As proven within the graph, every form of every pitch is damaged down by their Lefty and Righty areas. Inside this comparability, the benefit is much less apparent. The shapes are so related between the 2 teams that surmising a transparent benefit for one could also be overstating the importance of the proof. The one form that appears clearly higher than the opposite between the teams is the Sweeper. Lefties averaged roughly 2 extra inches of horizontal break on these pitches, whereas the vertical break was considerably related. Sweepers sometimes thrive on their capability to “sweep” away from the batter, making the common Lefty sweeper arguably more practical than the common righty model. It’s price noting that the pattern for these was decently smaller than the others, making a conclusion not as sound because it probably needs to be. Inside form knowledge, they’re roughly on a good taking part in area.

Provide and Demand

It’s well-known that there are extra righties on the earth than lefties. In response to one survey by BBC, solely 10-12% of the inhabitants is estimated to be left-handed. But, Fangraphs identified that 29% of all Innings Pitched are thrown by a Left-Handed arm. Lefties handle to pitch 2.64x greater than what their anticipated charge can be given the world inhabitants. Righties, alternatively, pitch at roughly 0.81x their anticipated charge. However to be sincere, even when one was not already conscious of the precise numbers, they may’ve made such assumptions about lefties being overrepresented in comparison with expectations within the baseball world. In any case, the age-going fable was that lefties have been inherently higher pitchers. However provided that they don’t seem to be besides in particular conditions (which many organizations are doubtless conscious of), then why does their inhabitants stay excessive?

For starters, roughly 30% of MLB hitters favor to bat from the left facet. This doesn’t imply that they’re essentially lefty, as plenty of right-handed throwers discover that they’re more practical at hitting from the left facet, whereas the identical typically doesn’t apply in reverse. This 2009 Hardball Times article by Steve Treder article states that there have solely been 57(!) from 1871-2009 (the minimal requirement is that the participant performed no less than one-half sport at a place aside from pitcher). The quantity has undoubtedly grown within the years since this analysis was printed, however it proves principally lefty throwers typically keep on with their facet. With this, a divide is created – if chosen from a random pattern of individuals, extra individuals are doubtless going to hit from the left facet than throw from the left facet. With the lefty-lefty matchup being so extremely beneficial to protection, it will justify the necessity for additional lefty pitchers to the extent of the inhabitants of left-handed hitters. This stays true normally, as having a bonus in such plate appearances can negate the drawback towards right-handed hitters. As that’s their solely important additional worth, it may be consequently argued that having Lefty pitchers is simply as helpful as what number of left-handed hitters are within the MLB inhabitants.

Because the inhabitants of lefty hitters naturally exceeds lefty pitchers, however such an equilibrium between the 2 can show worthwhile for protection, lefty pitchers will typically be paid extra relative to their stuff or capability to get outs. This was confirmed on this paper by Jarrett Korsen. And whereas the paper could haven’t used the popular baseball statistics, it does present that the distinction between Lefty and Righty pay is existent primarily based on notable numbers. The one logical rationalization for that is because of the lack of provide (relative to demand) and further worthwhile utility beforehand talked about. Such an alteration within the provide of Left-handed hitters would have an effect on each utility (the quantity of PAs the place the platoon benefit is current) and demand (extra/much less left-handed pitchers are wanted relying on the potential of with the ability to make the most of the platoon benefit). Holding these components in thoughts is essential in contemplating the worth construction behind a Left-handed Arm, and whether or not the benefit exists.

The Reply

Whereas it has been touched on all through the article, there nonetheless must be a transparent declaration – primarily based on the proof, lefty pitchers are solely additional beneficial and have a bonus for his or her inherent handedness when they’re dealing with a left-handed hitter. In addition to, in that distinctive scenario, all bets are off. When reviewing the efficiency from each side as a complete, they yielded virtually detached statistics in efficiency. After evaluating their “stuff” or “talent”, the numbers counsel that lefty pitchers could also be worse (on common) or barely equal to righties. And whereas they could be paid extra on account of their rarity out there, an LHP’s true worth is roughly equal to an RHP, supplied they don’t seem to be within the aforementioned situational matchup.

As acknowledged, the frequent dogma is that Lefty pitchers typically have a much bigger benefit on the mound than righties. From this proof, it’s pretty secure to conclude that that is false. Whereas that benefit does exist in sure spots, as a complete, it’s typically an unfaithful assertion. In fact, there are at all times exceptions to the rule – sure groups could flail towards left-handed pitching, however completely dominate righties, offering extra of a bonus for a singular matchup. Sure groups could discover lefties extra advantageous to their general roster, simply because of the variety of righties on their group and the necessity to diversify. However as a complete, it evens out. Given this, from an acquisition standpoint, it typically doesn’t make sense to think about one pitcher higher over the opposite solely on account of their handedness.

Creator’s Observe:

Whereas that is considerably digging into the weeds, an argument might be made to favor a left-handed pitcher over a right-handed pitcher, provided that their talent metrics have been even. To display this merely, let’s suppose two pitchers have about the identical arsenal. All of their pitches are roughly the identical, with an unmeaningful quantity of variation of their “stuff”. Choosing out a pitch, let’s suppose each of their sliders spin at 2600 rpm. Inside their respective handedness percentiles, the lefty can be ranked greater, because the group typically carries a decrease median for slider spin charge. And provided that LHPs and RHPs produce roughly the identical numbers with their respective talent metrics, then a better rating (from any class) can be most well-liked, because it’d produce higher numbers relative to the handedness. Ergo, it will make sense to favor the lefty in that scenario.

As a complete, it will be higher to reference their respective percentiles over their precise numbers, because the percentile scale for every produces the identical quantity of worth on common. Whereas their general benefit/drawback is probably not so totally different, differentiating between Lefty and Righty pitchers is a key a part of contemplating talent comparability.