Munro: Everything you need to know about catcher's interference
By Neil Munro
Canadian Baseball Network
One of the most common baseball trivia questions is, “How many ways are there for a batter to reach first base safely while taking a turn at bat?”
The most common answer to this question is that there are seven ways: a base hit, a walk, an error, a fielder's choice, being hit by a pitch, a dropped third strike and by defensive interference. Sometimes the defensive interference category is subdivided into two types – reaching base from a catcher’s interference (the catcher tips the bat as the batter swings at a pitch) and by obstruction – a defensive player bumps into the baserunner as he attempts to run towards first base after batting the ball in play.
On occasion, a more detailed response to this trivia question will also include activities that are not exclusively related to the actions of the batter or the defensive miscues of the opposing players. These extra situations include the extremely rare circumstances of spectator interference, fan obstruction, a pitcher tossing an illegal pitch, and the almost uncanny case of a game being suspended with a runner on first and then that player is traded prior to the makeup game being scheduled, in which case, another player can take his place as the base runner.
One of my own peculiar interests for many decades now, has been tracking the occasions of batters reaching base via defensive interference. These incidents are certainly quite rare – there are generally about 25 instances in a major league season in which a batter is awarded first base as a result of catcher’s interference and just one or two instances per decade of a batter being awarded first base because of defensive interference. The frequency of catcher’s interference calls per season is listed in one of the tables at the conclusion of this article for seasons in which the information is completely available.
Catcher's interference is a specific type of defensive interference that occurs when the catcher makes contact with the batter (or more likely his bat) during a pitch, or otherwise hinders or impedes a batter's ability to hit a pitched ball. In order for catcher's interference to be enforced, the batter must have been in a legal batting position with both feet within the batter's box. Catcher's interference usually results when the catcher is reaching forward for a pitched ball and his glove is hit with the bat as the batter swings.
In such cases, the catcher is charged with an error; however the batter is not considered to have reached on an error, and is not charged with a time at bat. The batter is credited with a plate appearance for statistical purposes, but reaching base safely on catcher's interference is not figured into calculating a player's statistical performance (such as batting average or on-base percentages). As well, if the ball is hit in play, the result is termed a “delayed dead ball,” meaning that the umpire should allow the play to continue until a point where no further action is possible and then call time and enforce such penalties or awards as required. If the ball is put in play and all runners, including the batter, advance at least one base, then play continues without further reference to the catcher’s interference. Any advances or outs stand in the official game account. (The rule is now specifically outlined in Rule 6.08 (c) in major league baseball’s official rule book).
Catcher's interference infractions are presumed to occur most frequently when a catcher squats too close to home plate, resulting in the batter's bat touching the catcher's mitt as the batter swings. This happens most often on attempted steals where the catcher is anxious to catch the ball as soon as possible and may move his entire body or mitt forward a bit.
I had also suspected that catcher’s interference might be the result of a catcher moving forward towards home plate in an attempt to corral a fluttering knuckleball but this was not born out on examination of the historical records of knuckleball pitchers. Certainly some batters have had a propensity for being the recipient of free passes to first base as a result of catcher’s interference instances, while the vast majority of players never receive such a call during their careers.
In delving through historical records, the first instance that I could find of a batter being awarded first base as a result of catcher’s interference (at least as noted in a game boxscore) was during the 1905 season. The lucky recipient of the free pass was John Anderson, an outfielder with Washington.
The first time in which the official rules of Major League Baseball actually mention the situation in which a batter should be awarded first base from catcher’s interference appeared in the rulebook used for the 1899 season. It is quite possible that one or more instances of catcher’s interference might have taken place between 1899 and 1905, but such instances (even up to the 1930’s) were extremely rare indeed.
Recently, the Baseball-reference.com site has allowed a complete search for instances of catcher’s interference occasions (using their batter event finder) for seasons dating back to 1930. From my own research, I have found just ten additional instances of catcher’s interference for seasons before 1930.
In the years between 1930 and 1959, the average number of catcher’s interference calls (or CI) was about six per season. Twice there were just two instances of CI in a season (1947 and 1955) and the high count for that period was 13 (in 1938).
Beginning in the early 1960s, the number of CI instances increased significantly. This period did coincide with baseball’s first expansion and the lengthening of the season to 162 games, but the frequency of CI instances per game also increased significantly after 1961. The CI annual count exceeded 30 for the first time in 1987 (when 31 instances were charged) and the highest total ever recorded actually occurred last year when 43 CI occasions were logged. There were 41 CI occurrences in 2016.
One of the tables below lists the average number of CI instances per decade. There have been just 1,356 CI instances in major league regular season play since 1930 (and very likely fewer than 25 such occasions before 1930).
There were five CI calls made during World Series games and another nine CI instances charged in other post-season playoff action. No CI calls have ever been registered in All-Star game competitions. Just six players have been the beneficiary of receiving a free pass via a CI twice in one game, for a total of seven instances: Ben Geraghty (1936), Pat Corrales (1965, twice), Dan Meyer (1977), Bob Stinson (1979), David Murphy (2010) and Jacoby Ellsbury (2015). Ellsbury is the only one among these players to have the interference charged against two different catchers.
I also did a statistical analysis to determine if CI instances happened randomly or actually occur as a result of some “skill” possessed by a certain type of batter. My findings clearly show that these instances do not occur randomly at all. Most players with very long careers did not record a single instance of getting a free pass as a result of a CI instance. Among the all-time plate appearance leaders, Hank Aaron, Rickey Henderson, Cal Ripken Jr., Eddie Murray, Stan Musial, Barry Bonds, Derek Jeter, Willie Mays, Robin Yount, Alex Rodriguez, Rafael Palmeiro, Omar Vizquel and Brooks Robinson had zero CI instances called in almost 190,000 times collective coming to bat. On the other hand a player like Ben Geraghty had three CI instances during his 159 career plate appearances.
The major league record for CI instances is now held by the Yankees’ Jacoby Ellsbury, with 31 CI occasions. Ellsbury just passed the former record holder, Pete Rose (with 29 CI) during the 2017 season. Ellsbury is also the major league record holder for CI instances in one year, having received 12 free passes of this type in 2016. When Pete Rose played briefly with the Montreal Expos during the 1984 season, I had the opportunity to watch him on TV for several of his games. On at least three occasions, Rose turned (pointing to the catcher) and asked the ump to rule that his bat was tipped as he swung. (He was denied the call each time.) Clearly Rose wanted to get on base by any means possible and he likely asked for a CI call many times while playing with the Cincinnati Reds.
On the other hand, a list of the greatest home run sluggers of all time did not produce a single CI instance. Babe Ruth, Lou Gehrig, Jimmie Foxx, Mel Ott, Ted Williams, Mickey Mantle, Eddie Mathews, Ernie Banks, Harmon Killebrew, Mike Schmidt, Gary Sheffield, Manny Ramirez, Mark McGwire, Sammy Sosa, Ken Griffey, Jim Thome, Albert Pujols, as well as the aforementioned Aaron, Bonds, Mays, Rodriguez, Palmeiro and Murray never got a free pass as a result of catcher’s interference once. This group of sluggers amassed more than 14,000 homers in their collective careers. Perhaps (unlike Rose) they shrugged off any instance of their bat being accidentally tipped by a catcher in the hope of taking one more healthy cut at another long ball.
Canadians have been awarded defensive interference calls on just six occasions, with the unlikely career leader being pitcher Ryan Dempster with two such cases (in his 688 career plate appearances as a batter). The other Canadians (each with 1 DI awarded) were Reno Bertoia, Pete Ward, Matt Stairs and Terry Puhl. Puhl was actually presented with a free pass to first base a as result of defensive obstruction and not from a catcher’s interference (in 1980).
The career leaders for Defensive Interference (and all here are actually CI instances) are listed here. The list includes a variety of sluggers, singles hitters and defensive specialists.
The teams with the most CI during a single season are also listed here:
The average number of CI instances called by decade (in regular season play) follows here:
Finally, some noteworthy observations concerning these CI “accomplishments” are presented below.
- Chris Short had an average of one CI for each of 71.5 plate appearances (the highest frequency of anyone in the top 20 career leaders.
- Phil Niekro was the pitcher for 14 career CI instances called (the most by far for any pitcher).
- Chris Short and Nolan Ryan were tied for second among pitchers with six career CI instances.
- Chris Short was the pitcher or batter for a total of 17 CI instances.
Complete records are known only for the seasons from 1930 to 2017 although the frequency of CI instances was significantly smaller for years before 1930.
Progressive Season and Career CI records (through the 2017 season)
I have campaigned (mostly in complete obscurity) to have the formula for determining a player’s on-base percentage changed to include DI instances as counting towards the number of times a player reaches base safely. The existing formula for OBP is: (H + BB + HBP)/(AB + BB + HBP + SF). I prefer changing it to read: (H + BB + HBP + DI)/(AB + BB + HBP + DI + SF) but MLB has not seen fit to act on my request. The noted American baseball historian, Bill Deane, has actually argued that instances of a batter reaching base via an error or a dropped third strike (and a DI) should also be included in the formula for calculating his on-base percentage. The argument suggests that the batter did not use up one of the 27 outs that are granted to his team in reaching base safely by any of these means, and he should receive credit for it.
Many collectors and hobbyist spend a great deal of time and money collecting very rare paintings, gems and other unique commodities. My own personal interest has been to try to accumulate the complete statistical record of defensive interference instances. If nothing else, it does not require a great monetary expenditure to track down these cases, just long hours and a great deal of patience!