First Class: The Ongoing Transformation of the Leadoff Hitter

More teams are leaning to putting a guy who gets on base in the leadoff spot. The days putting your fastest guy in the leadoff spot are over. The key is, ‘Can you get on base?’ That’s something that’s being valued more.”
–Matt Carpenter, interview with Rick Hummel, June 2016

Matt Carpenter made this comment in mid-June, right in the middle of a brilliant first half out of the leadoff slot for the Cardinals. His conclusion is certainly intuitive in the connotation. Say “leadoff hitter” to most fans of the game and the phrase will conjure images of baseburgling demons like Rickey Henderson, Lou Brock, Maury Wills, Tim Raines and Vince Coleman — players best known for their speed and gaudy stolen base totals. And most fans assume that those type of players are mostly products of a bygone era, replaced by players with more modest stolen base totals and more diverse skill sets. That said, there’s a lot to unpack in Carpenter’s comment. How accurate is the statement, and how has the leadoff hitter’s modes of production changed from generation to generation?

First, let’s establish some ground rules. I wanted to determine several categories that gauge a leadoff hitter’s production. The two most obvious are on-base percentage (OBP) and slugging percentage (SLG). While Carpenter didn’t specify slugging ability out of the leadoff slot, there are sure to be historical trends in extra-base pop. But slugging percentage tells only part of the story and it includes singles. To get a more accurate picture, let’s include the isolated power (ISO) of leadoff hitters.

Additionally, Carpenter rightly mentioned the importance of reaching base, and walks are one of the best tools a leadoff hitter can have in his kit. That being the case, we will want to include walk percentage (BB%). Finally, speed is a significant part of Carpenter’s quote, and there are several ways to gauge it. No single number is a magic bullet for speed, so I’ll include the following: stolen base success rate (SB%), stolen bases per time on base (SB/OB), and Bill James’ speed score (Spd) using a formula on an old Baseball Think Factory page. It’s worth noting, however, that the wide-ranging variety of leadoff hitters in any given year made the defensive positional adjustment futile. As such, it isn’t included.

I collected data for these categories for all leadoff hitters for every season in which full data was available. The 2016 data are through the end of the first half. This includes all seasons since 1920 (except for Spd, which can accommodate full data for the formula beginning only with 1939). I then normalized the data (except for Spd) by placing it on a 100 scale, compared against the major league average of all non-leadoff hitters.

This differs slightly from typical normalized statistics in that the numbers aren’t being compared to the full major league average. Since we’re looking at a very specific demographic (leadoff hitters), we want to compare those data to the other, non-leadoff group. Call it major league average minus leadoff hitters. Last but not least, to identify intermediate and long-term trends, I’ve presented the data as five and 10-year rolling averages. The beginning year for all charts is 1924 (except for Spd, which is 1943).

On-Base Percentage and Slugging Percentage

While there have been many peaks and valleys in on-base percentage and slugging percentage for leadoff hitters, the variation has been relatively mild. Using the five-year rolling average, leadoff hitters have had OBP+ as low as 97.3 (almost exactly the same as the rest of hitters), and the high point was 104.9. The gap between the biggest and smallest OBP+ for leadoff hitters in our sample is less than six percent. Use the 10-year rolling average and the gap shrinks even further, with a high of 104.0 and a low of 97.9. The results are similar, though slightly more pronounced, for slugging percentage (SLG+). The five-year high is 97.3, and the five-year low is 87.4 — a gap of 9.9 percent. Expand it to a 10-year average and it’s a low of 88.8 and a high of 96.4, a gap of 7.6 percent.

There’s a firm conclusion to be drawn here. Regardless of era, teams have selected a specific kind of hitter for the leadoff slot. These hitters get on base at a slightly higher clip than the rest, but the aggregate figure is not exaggerated. In 63 of the 97 seasons in the sample, leadoff hitters got on base more frequently than the rest. However, only four of those seasons were more than five percent higher than the rest of the league, and the largest gap was 6.1 percent higher than league average. 24 more of those 97 seasons were between 98 and 99.9 percent of major league average, just a tick below the rest.

The power of leadoff hitters also fits a specific mold. The overwhelming majority of seasons see leadoff hitters running up a major league-relative slugging percentage from 0.1 to 10 percent lower than the rest of the hitters, with 80 of the 97 seasons satisfying that range. No single season exceeds the major league average mark, but 1988 came closest with 99.9 percent. The leadoff hitter low mark was a scant 81.9 SLG+ in 1961, which is 5.5 percent lower than the second worst mark.

In summation, there’s plenty of year to year variation but the variance is minimal. Leadoff hitters in any given season will almost certainly fall slightly better than the rest in on-base percentage, and slightly worse than the rest of the league in slugging percentage. Let’s dig deeper into a few of the unique ways that OBP and SLG may be amassed–walk percentage and isolated slugging.

BB% and ISO

This is where we start to see some traction among the trends. Most alarming is how much BB% has fluctuated among leadoff hitters since 1920. There are five distinct eras.

The Early Years (1920-1944)

Early leadoff hitters in our sample walked at much higher rates than others. The five-year BB%+ rolling average for leadoff hitters didn’t dip below 110 until 1934. In fairness, this is mostly a function of the rest of the hitters walking at very low rates — many of the lowest raw, non-adjusted walk rates of the sample (at eight percent or lower). Still, managers were clearly employing players with an impressive ability to walk compared to their peers for the leadoff slot. Beginning in 1927, leadoff hitters’ relative BB% began a slow descent. From 1930 to 1944, the five-year rolling average BB%+ decreased or remained the same every single year.

The Eddie Years (1944-1960)

The downward trend reversed beginning in the mid-40s on the backs of three Eddies–Stanky, Joost and Yost. This trio collectively amassed a sparkling 18 percent walk rate when active from 1947 to 1960 while the rest of the major league hitters were routinely coming in between nine and 10.5 percent. Each year from 1945 to 1956, leadoff BB%s were 9.8 percent or higher, and didn’t dip below 8.9 percent until 1963. From 1945 until 1960, leadoff BB%s were six percent or more higher than league average eight times.

The Waterbug Era (1964-1980)

The Eddies progressively retired and the leadoff BB% crash-landed with their departure, eventually sinking to a new low by the mid-1960s. Leadoff hitters from 1960 to 1965 were impacting the game in different ways, but reaching base via walk was not one of them. Waterbugs like Luis Aparicio, Maury Wills, Tony Taylor and Don Blasingame racked up the highest amount of leadoff playing time in that era and each possessed BB% below major league average. From 1964 until 1980, the five-year rolling average remained below major league average, sinking as low as 87.4 in 1969. We’ll see later how this set of leadoff hitters changed the game, even if their BB% was poor.

Rickey’s Rebellion (1980-1995)

The thaw began around 1976, and walk percentages really started to repair themselves among the leadoff crowd when Rickey Henderson arrived on the scene. Of course, Henderson had help. Players like Willie Randolph and Davey Lopes, and unconventional leadoff choices like Bobby Bonds and Mike Hargrove, had very stable walk rates at the end of the ’70s. Henderson and Randolph continued the impressive BB% into the 80s, and combined with their peers, took leadoff hitters to a BB% peak not seen since the 1920s.

Managers continued the Hargrove experiment by giving loads of leadoff time to players like Wade Boggs, Tony Phillips and Brian Downing — the exact type of players who never would have seen the leadoff role in the Waterbug era, yet still had an impressive knack for drawing a walk. From 1981 to 1995, the unconventional choices were complemented by leadoff monsters like Henderson and Tim Raines. Speedsters like Craig Biggio, Brady Anderson, Lenny Dykstra and Brett Butler more than held their own in their ability to draw a walk.

The 21st Century and Recent Events

The tide had turned for leadoff hitters taking walks and remained strong into the 1990s (the late ’90s dip in BB%+ had more to do with other, non-leadoff hitters experiencing a spike in their BB% than any decline in leadoff BB%) until the early 2000s. Then it took another shift downward thanks to gobs of plate appearances for leadoff hitters like Juan Pierre, David Eckstein, Fernando Viña, Brian Hunter, Doug Glanville and Ichiro Suzuki. For all of their tools and reasonable productivity in most cases, that set of leadoff men fared poorly at taking walks. And both the five and 10-year trends have remained below major league average since the early 2000s. To Carpenter’s point, however, there has been a mild uptick in the last few years. Of course, this uptick has a lot to do with Carpenter himself, along with Dexter Fowler and improved walk percentages from Brett Gardner and Curtis Granderson.

Historical ISO+ and Carpenter’s New Charge

While leadoff walk rates have mostly hovered above their non-leadoff peers, leadoff men’s isolated slugging has frequently been considerably worse than their peers. Even the best five-year rolling average has been more than 10 percent below the rest of the majors. At its worst, in the early 1960s, the five-year rolling average approached 30 percent worse than the rest. The 10-year ISO+ for leadoff hitters started low and headed for the basement over a 40-year span, with intermittent starts and stops on the way down. It wasn’t until the 1965 to 1980 group of leadoff hitters came along that the trend reversed. Those hitters were collectively mediocre at taking a walk but they presented enough pop to at least return leadoff power to 1930s levels. This was primarily a result of contributions from Rick Monday, Bobby Bonds, Tommie Agee, Felipe Alou and Dick McAuliffe, and intermittent leadoff time for the aforementioned Mike Hargrove, Lee Mazzilli, Joe Morgan and Don Money.

After a mild cool-off period, late ’80s hitters sent leadoff ISO higher thanks to Boggs, Henderson, Raines, Molitor, Downing, Barry Bonds, Ellis Burks and Lou Whitaker, among so many others. And like the late ’90s dip in BB%+, the late ’90s dip in leadoff ISO+ had much more to do with the explosion of power across the game and leadoff hitters’ inability to expand at the same rate.

It’s in the ISO+ rebirth of 2005 until present day that we really see how leadoff hitters have changed recently. In the Moneyball and Beyond era, teams are increasingly selecting powerful hitters for the leadoff slot. Alfonso Soriano, Hanley Ramirez, Granderson, Grady Sizemore, Ian Kinsler, Jimmy Rollins, Rickie Weeks and (surprise!) Matt Carpenter have all racked up 400 or more games at leadoff with ISO of .180 or higher — considerably above major league average. Over the last decade, this has been the reinvention of the leadoff man. Four of the five highest single season ISO+ from leadoff hitters have happened since 2008. Every seasons since 2008 ranks in the top 13 five-year ISO+ rolling averages. And while that’s still 14 percent below major league average, it’s also an extended period of power from leadoff hitters that’s unprecedented since 1920. Matt Carpenter was right to assert that leadoff hitters are different, but he misidentified the way that they’re different. And ironically, he’s the leadoff hitter who best exemplifies the new order.

Speed Measures (Success Rate, Stolen Bases per Time On Base, and Bill James’ Speed Score)

Amazingly, the stolen base success rate of leadoff hitters didn’t have a five or 10-year period above league average until 1959. For the 34 of the first 37 years of the data set (1920–1956), leadoff hitters were actually worse than the rest major leaguers at successfully stealing bases. They were frequently considerably worse, with 18 of those 37 seasons coming in 15 percent or more worse than their non-leadoff peers. And yet, leadoff hitters were racking up stolen bases per time on base (SB/OB) at higher and higher rates throughout that era, starting with a five-year trend that was two percent more than league average and expanding all the way up to a five-year peak of 98.3 percent more than league average in 1946. They were attempting far more steals, yet succeeding less.

The Waterbug Era (1960-1980 for these purposes) changed all of this. Their walk percentage cratered in this era, but they significantly amplified speed in the leadoff slot. Success rates skyrocketed, as did SB/OB. Success rate has been above league average — and mostly well above league average- ever since. The most obvious drivers of this revolution were Lou Brock and Maury Wills, but they were far from the only players. In the ’60s, it was Luis Aparicio, Jose Tartabull, Jake Wood, Bert Campaneris, and Tommy Harper joining Brock and Wills, with all possessing success rates of 76 percent or better. The ’70s added to the 76 percent or better group with Davey Lopes, Willie Wilson and Julio Cruz (80 percent or higher success rates), plus Bake McBride, Paul Molitor, Bobby Bonds, Omar Moreno and Ron LeFlore.

Of course, the dip in walk percentage and mild ISO increase in the 1970s in particular meant that leadoff hitters weren’t starting on first base as frequently. They were doubling more and walking less. And that led to a mild dip in SB/OB, only for it to come back with a vengeance in the 1980s. Rickey, Raines, Moreno, LeFlore and Cruz all contributed significantly from 1980-1990, but the biggest culprit was Vince Coleman. The leadoff man for the Whiteyball Cardinals consistently racked up SB/OB at 10 times the rate of non-leadoff hitters. He was even 7.7 percent higher than the second best leadoff man of the era, LeFlore, and 11 percent higher than the third place Henderson.

The 1990s saw five and 10-year leadoff Speed scores crystallize in the 3.9 to 4.1 range (keep in mind that this excludes a defensive adjustment), with only a mild bump to the five-year figure around 2011 and 2012. The five and 10-year success rate for leadoff hitters has been in a mild but steady decline in that same era, with recent five-year figures falling to 1950s pre-Waterbug era numbers. And the stolen bases per times on base seem to be reaching crater stage, with the lowest five-year average in more than 30 years.

Was Matt Carpenter right?

Carpenter’s assertion was that more teams are selecting leadoff hitters with a high OBP, frequently at the detriment of the speed that most fans associate with the leadoff slot. Carpenter was slightly correct about OBP, as recent leadoff hitters are starting to reach base more. However, it’s a very mild upturn. The same is true of walk percentage, which has had a nice little run for a few years but is merely returning to late ’90s/early 2000s numbers in the overall picture.

Carpenter was definitely correct about the de-emphasis of speed in the leadoff slot, as Speed scores, stolen base success rate, and stolen base frequency are fading. However, Carpenter buried or even flat out ignored the lede — the significant upward turn in power (ISO+) from leadoff hitters. There’s more thunder from leadoff hitters than we’ve seen going all the way back to 1920. We’re entering a new era for leadoff hitters- an era where their power more closely resembles the No. 2 through No. 9 hitters. ISO rates are higher than they’ve ever been and show no signs of regressing any time soon.

References & Resources

• Rick Hummel, St. Louis Post-Dispatch, “Carpenter entrenched at leadoff for Cardinals”
• Baseball-Reference Play Index
• FanGraphs
• Tom Ruane, Baseball Think Factory, “Figuring Speed Scores”