Are There Benefits to Sibling Rivalry?

Brothers B.J. and Justin Upton are now both Braves, thanks to the November signing that brought B.J. to Atlanta and the trade last month in which Justin joined him.  As one would expect, the Uptons are excited about the opportunity to be big-league teammates, which they’ve dreamed of for years.

B.J. has been quoted in the press about how “exited” and “looking forward to [playing together]” they are.  “We’ll definitely push each other. It’s just kind of understood.”

Over the past few seasons, both Uptons have been considered underachievers, with sportswriters speculating about makeup, effort and attitude problems.  Perhaps these are genuine issues, or perhaps they are just a convenient way to explain why two players who were each once ranked the second-best prospect in baseball have yet to become superstars.

But now the brothers are excited, planning to push each other.  If clubhouse chemistry exists, and if it positively improves on-field performance, than it seems logical that playing with one’s brother should improve one’s performance.  As one of the articles linked above puts it, after listing some of the Uptons’ stats, “Now playing in the same outfield, those numbers could get even better as a result of classic sibling rivalry.”

So has there really been any performance boost associated with siblings in the same clubhouse in the past?  One place we can look is in the clubhouse of the New York/San Francisco Giants, where 13 brothers have been teammates:

Felipe, Jesus & Matty Alou (1963)
Felipe and Matty Alou (1960-62)
Jesus and Matty Alou (1964-65)
Jesse and Virgil Barnes (1919-20, 1922-23)
Mort and Walker Cooper (1947)
Buck and John Ewing (1891)
Al and Danny Gardella (1945)
Christy and Henry Mathewson (1906-07)

But to qualify for my very limited study, the brothers had to have had some major-league experience before becoming teammates, because we can’t apply a normalizing metric like OPS+ or ERA+ based on minor-league data from way back when and because we need a no-brother baseline for comparative purposes.  I limited this sample for our purposes a bit further by looking only at the first season that two brothers played together (except for a couple of cases where one of the brothers made very few plate appearances or pitched to only a few batters in that first season, in which case I counted their second season instead).  If there is some sort of “brother boost,” it would show up in the siblings’ stats in their first season sharing a clubhouse.

So I next compared the OPS+ or ERA+, as appropriate, of the brothers in the year before they were together to the first year they were together.  Here’s what we get:

The first thing to note is that this is a good group of hitters.  It includes a Hall-of-Famer and three others who had at least one top-10 MVP finish.  The pitchers are good, too, with one Hall-of-Famer, and though as a group they predate the Cy Young Award, they would have won some had it existed.  Mort Cooper won the NL MVP award in 1942 (though not as a Giant) and placed in the top 10 two other times.

Just for fun, let’s take a look at these Giant brothers:

Buck Ewing, a future Hall-of-Famer and a great hitter (Connie Mack, a catcher himself and man who’d managed Mickey Cochrane, stated unequivocally that Ewing was the game’s greatest catcher — ever), had been playing for the Giants since the franchise had been in Troy, New York, in 1880.  Both Buck and his brother John, though, played for the New York franchise in the short-lived Players League in 1890, and when that effort collapsed, Buck returned to the Giants for 1891, and his brother, a pitcher, came with him.  But in 1891, Buck injured his throwing arm, and only played in fourteen games.  Still, in those 14 games, he hit for a 150 OPS+.  Although he would be healthy in 1892 and hit even a bit better, the Giants made the intelligent move and traded him to the Cleveland Spiders in 1893, ahead of what would be a steep decline.  If anyone got a boost from playing with his brother, it was John, who would pitch 269 innings and lead the league in ERA (2.27) and have an ERA+ of 139.  (He’d been an average or worse pitcher in his previous three major-league seasons.)  But that would be his last season in the majors, for he was struck with a serious illness in the winter, and never really recovered, dying in 1895 at the age of 31.

Henry Mathewson was recommended by his brother Christy to John McGraw at a time in 1906 when the Cubs were so far ahead of the Giants in the standings that it didn’t matter who pitched for the Giants.  Henry pitched a complete game on September 28, giving up seven runs, while walking 14 and hitting one batter.  He would pitch only two more innings over the course of two years, and convinced McGraw, according to Ray Robinson, that “pitching talent was hardly an inherited Mathewson characteristic.”  Christy himself in 1906 had his worst season since the 33 innings he’d pitched for the Giants as a nineteen-year-old in 1900, with an 88 ERA+.  Giant hitting would bail him out, and allow him to win 22 games, though.  Although 1906 was Henry’s first year in the majors, and the Mathewson’s were thus not included in data above, it seemed that neither brother succeeded in inspiring the other.

Boston Braves pitcher Jesse Barnes was traded to the Giants in 1918 with Larry Doyle in exchange for Buck Herzog.  Barnes would be an excellent pitcher with the Giants until being traded back to Boston in 1923. In 1919, his 22-year-old brother Virgil joined the Giants, but he only pitched a total of nine innings in two seasons. Finally, in 1922, Virgil was able to break onto the roster, primarily as a reliever. In 51 innings he had an ERA+ of 116, almost 30 points better than in his brief cup of coffee in 1920. Virgil’s performance fell, though, as he went from an ERA+ of 120 in 1921 to one of 115 in 1922.  But given the high quality of his performance, year in and year out, the Giants couldn’t complain — particularly since they won the World Series in both 1921 and 1922.

Danny Gardella is most famous for jumping to the Mexican League in 1946 and subsequently suing Organized Baseball, claiming the reserve clause violated the Sherman and Clayton Antitrust Acts.  Gardella played left field and first base for the Giants in 1944-45, and hit well, with a 115 OPS+.  But of course, this was wartime baseball, and it should be understood that the pool of major leaguers contained few stars, most of whom were in the military.  His brother Al, already 27, made it to the Giants for 33 plate appearances in 1945, hitting .077/.226/.077, for an OPS+ of -14!

The Giants bought catcher Walker Cooper from the St. Louis Cardinals for $175,000 in 1946, and he would hit well for them (116 OPS+) in three-plus seasons.  The Giants would acquire his brother, pitcher Mort Cooper, from the Braves in June 1947.  Already 34 and in his last full season in the bigs, Mort would, in eight starts, pitch poorly (58 ERA+).  Whether Walker was inspired by his brother’s presence is hard to say.  He was already having a heck of a season before Mort joined the Giants.  (He hit .305/.339/.586 for a 140 OPS+ that year. On the day of the trade, he was at .284/.335/.516, so perhaps was inspired just a bit.) He hit 35 homers on a team that set a then-major-league record of 221 home runs in a season.

Felipe Alou, then 20, was signed as an amateur free agent by the New York Giants in 1955 out of the Dominican Republic.  He made the big club in 1958, its first year in San Francisco.  Felipe’s brother Matteo got a cup of coffee in 1960, but played in 81 games with 217 plate appearances in 1961, having by far his best year as a Giant: .310/.356/.455 for a 118 OPS+.  Felipe hit better, too, raising his OPS+ from 98 in 1960 to 113 in 1961 with a .289/.333/.465 campaign.  In 1963, the two Alou brothers became three when Jesus got 25 plate appearances with the Giants.  But after the season, Felipe was traded to the Milwaukee Braves.  Jesus would never be a good hitter, and in 1964 his .274/.305/.327 led to an OPS+ of 77.  Matty faltered, too, hitting .264/.302/.308 for a 71 OPS+.

If the Giants brothers are any indication, brothers inspiring each other to better performance is a very mixed bag, and we can’t really be sure whether any brother’s performance was better than to be expected because we don’t have a projection system such as PECOTA for these early years to help us determine what a player should be expected to do in any season.  Some players might be more likely than others to get a boost from playing alongside a brother.  Perhaps the Uptons will get such a boost.