As a lefty coming into 9U Child-Pitch, coaches made certain at a younger age that I knew how you can pitch. Lefty baseball gamers from all world wide will seemingly inform the same 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 sorts utilizing this data consciously or subconsciously to affect their selections. And whereas typically this dogmatic recommendation may be statistically true, the vital error is available in taking the information at face worth. Is there any precise fact to this lore? There have been a number of appears at the same 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 variety of surrounding factors. In acknowledging all of those elements, one can digest the difficulty as an entire.

The Preface: Platoon Benefit

Earlier than diving into this, there’s a vital premise that must be re-established – the platoon benefit does exist. Most notably confirmed in The E-book: Enjoying the Percentages in Baseball, it must be identified that lefty pitchers have a bonus in opposition to lefty hitters, and righty pitchers have a bonus in opposition to 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 fundamental proof of the premise on this piece. Utilizing information 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 clear within the desk, Proper-Handed Pitchers did about 15 factors higher in opposition to the same-handed hitter, and Left-Handed Pitchers did about 32 factors higher than the same-handed hitter. With this information being over a good pattern of years (10) and nonetheless being considerably sizeable, it is rather secure to once more conclude that Tom Tango was proper. With that etched in stone, the potential benefit or disadvantages of Lefties shall be a lot simpler to show.

Handedness Pitcher Worth As A Entire

Most likely probably the most primary look of the entire article, exhibiting the general worth of Lefties and Righties as an entire, no matter matchup, may give a great sense of if one noticeably has a bigger benefit. As an entire over the pattern, Lefties’ wOBA in opposition to is 0.315471, whereas Righties’ wOBA in opposition to 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 advised with OPS in opposition to, as each side averaged 0.727. With reference to their capability to get outs themselves whereas limiting free passes (Okay% – (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 an entire, 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 12 months the place one hand completely outshined the opposite? Right here is the wOBA of every hand, by 12 months.

Just one 12 months 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 12 months over a big pattern of seasons. Therefore, that is nonetheless not sufficient to show utilizing one could 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 may 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 actual fact of benefit stays fixed, the precise levels of those benefits are a lot completely different. Reiterating from above, Lefties did 32 factors higher in opposition to 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 optimistic platoon benefit (as proven) equals a decrease wOBA allowed. Over the whole thing of the pattern, the Lefty wOBA platoon distinction stays considerably larger, with the 2 strains not overlapping as soon as. That unfold was maximized in 2021 when LHPs had been gaining 40 factors off of the platoon in comparison with the RHPs’ 12 factors. In opposition to 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. On condition that they’re each at a considerably equal drawback, the potential matchup exploitability of a Lefty might show a degree concerning an additional sense of worth.

Each of those factors show, to an extent, a way of additional worth for Lefty Pitchers. It showcases a degree of exploitability for which sure particular conditions make them helpful. And whereas the combination statistics present no such distinction, the optimization of those conditions might in the end show to make Lefties extra helpful as an entire compared to Righties. After all, there are certain to be diminishing returns regarding this, which shall 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 information solely from the 2022 season, these charts present ample proof of that:

Inside the common velocities, Righties had been the winners for each one of many main pitches used within the information. Whereas some pitches had been by wider margins than others, main in each potential pitch reveals that their capability to pitch at larger than lefty speeds is existent. The Spin charge story is rather less simple.

Of the 7 pitches that had 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 guide 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 total 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 usually thrive on their capability to “sweep” away from the batter, making the common Lefty sweeper arguably simpler than the common righty model. It’s value noting that the pattern for these was decently smaller than the others, making a conclusion not as sound because it probably must be. Inside form information, they’re roughly on an excellent enjoying subject.

Provide and Demand

It’s well-known that there are extra righties on this planet than lefties. In keeping with 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 could be given the world inhabitants. Righties, then again, pitch at roughly 0.81x their anticipated charge. However to be sincere, even when one was not already conscious of the precise numbers, they might’ve made such assumptions about lefties being overrepresented in comparison with expectations within the baseball world. In spite of everything, the age-going fantasy was that lefties had been inherently higher pitchers. However provided that they aren’t besides in particular conditions (which many organizations are seemingly conscious of), then why does their inhabitants stay excessive?

For starters, roughly 30% of MLB hitters desire 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 simpler at hitting from the left facet, whereas the identical typically doesn’t apply in reverse. This 2009 Hardball Instances article by Steve Treder article states that there have solely been 57(!) from 1871-2009 (the minimal requirement is that the participant performed at the least one-half sport at a place aside from pitcher). The quantity has undoubtedly grown within the years since this analysis was printed, but it surely proves largely lefty throwers typically keep on with their facet. With this, a divide is created – if chosen from a random pattern of individuals, extra persons are seemingly going to hit from the left facet than throw from the left facet. With the lefty-lefty matchup being so extremely helpful to protection, it could justify the necessity for additional lefty pitchers to the extent of the inhabitants of left-handed hitters. This stays true on the whole, as having a bonus in such plate appearances can negate the drawback in opposition to 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 as a result of 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 opportunity of having the ability to make the most of the platoon benefit). Protecting these elements in thoughts is vital 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 helpful and have a bonus for his or her inherent handedness when they’re going through a left-handed hitter. In addition to, in that distinctive scenario, all bets are off. When reviewing the efficiency from each side as an entire, they yielded nearly detached statistics in efficiency. After evaluating their “stuff” or “talent”, the numbers recommend that lefty pitchers could also be worse (on common) or barely equal to righties. And whereas they might be paid extra attributable to their rarity out there, an LHP’s true worth is roughly equal to an RHP, supplied they aren’t within the aforementioned situational matchup.

As said, 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 an entire, it’s typically an unfaithful assertion. After all, there are all the time exceptions to the rule – sure groups could flail in opposition to 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 total roster, simply as a result of variety of righties on their crew and the necessity to diversify. However as an entire, it evens out. Given this, from an acquisition standpoint, it typically doesn’t make sense to contemplate one pitcher higher over the opposite solely attributable to their handedness.

Writer’s Observe:

Whereas that is considerably digging into the weeds, an argument could possibly be made to desire a left-handed pitcher over a right-handed pitcher, provided that their talent metrics had been even. To exhibit 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”. Selecting out a pitch, let’s suppose each of their sliders spin at 2600 rpm. Inside their respective handedness percentiles, the lefty could be ranked larger, 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 the next rating (from any class) could be most popular, because it’d produce higher numbers relative to the handedness. Ergo, it could make sense to desire the lefty in that scenario.

As an entire, it could 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 total benefit/drawback is probably not so completely different, differentiating between Lefty and Righty pitchers is a key a part of contemplating talent comparability.