Basic Pitcher Statistics

Pedro Martinez pitched in the Majors for 18 years with 5 teams. He excelled at many of the fundamental pitching aspects of the game, and for this reason, he was elected to the Baseball Hall of Fame in 2015.

In baseball, it is crucial to know how to routinely field a grounder before you can learn how to turn a double play. In the same way with statistics, understanding the basics is necessary before learning more advanced metrics. These basic baseball statistics are ones that have been around since even before Babe Ruth’s time. A fundamental understanding of baseball and/or experience playing at any level will likely have allowed exposure to most or all of these statistics. This may serve as a good refresher if it has been awhile, or if just now working into some of the more complicated metrics. This article will serve as a quick learning course for the basics.

Games |G|

This statistic represents the number of games a pitcher has pitched in over a period of time. Games is a  counting statistic, increasing consistently by one for each game pitched. Games are interchangeably referred to as “appearances” in conversation, but statistically will always be represented as above. A pitcher receives credit for a game regardless of how many pitches he throws.

Games Started |GS|

This statistic is similar to Games and represents the number of games a pitcher has started over a period of time. Again, Games Started is an example of a counting statistic.

Innings Pitched |IP|

Innings pitched indicate how many outs a pitcher has recorded. Each time a pitcher records an out (either by strikeout, groundout, flyout, fielder’s choice, etc.) they receive credit for 1/3 of an inning. This is numerically represented as 0.1 innings, to indicate 1 out. This is read as “one-third innings”. Similarly, 2/3 of an inning, or 2 outs, is represented as 0.2 innings and 3 outs is 1 inning. When calculating statistics, it is important to remember to convert this number into the appropriate fraction. If this does not occur the arithmetic will not be performed correctly, and the statistic will be inaccurate.

Walks |BB|

Walks are accrued when a pitcher allows a batter to reach base via a base on balls (hence, BB). This occurs when a pitcher throws 4 pitches that are called as balls in a plate appearance. Walks are used as a representation of a pitcher’s ability to control their pitches. The less walks issued, the more control they are thought to have.

Intentional Walks |IBB|

Intentional walks are walks that a pitcher deliberately issues, normally at the instruction of his manager for tactical reasons within the game. The primary reason is that the manager perceives the next batter in order as considerably less skilled than the current one. This avoids the current batter having an opportunity to create runs with his bat.

Strikeouts (SO or K)

Strikeouts occur when a pitcher tallies three strikes against a batter, thus recording an out for his team. Statistically, strikeouts are seen as the counterpart to walks; while walks indicate a pitcher’s control, strikeouts are viewed as an indication of a pitcher’s power or “stuff”.

Hits |H|

This statistic represents the number of hits allowed by a pitcher. Refer to Basic Hitter Statistics for more information.

Home Runs |HR|

This represents the number of home runs allowed by a pitcher. Refer to Basic Hitter Statistics for more information. Home Runs are one of the most exciting plays to occur in the game, but not for the pitcher who allowed it!

Runs |R|

Runs represent the number of runs scored (both earned and unearned) for which a pitcher is responsible. As explained above in the definition for losses, a pitcher is responsible for the run when a batter he allows to reach base scores, regardless of which pitcher is in the game at the time.

Earned Runs |ER|

Earned runs are similar to runs, but are only assigned to a pitcher if the runner in question did not reach base due to an error, passed ball, etc. This is a very basic explanation, and for a more nuanced one, consult the official MLB Rule 10.16.

Earned Run Average |ERA|

Earned Run Average (or ERA) represents the average number of earned runs a pitcher allows in a nine-inning span, given to 2 decimal places. ERA is calculated by dividing the total number of earned runs by the number of innings pitched and multiplying by 9. Mathematically, this is displayed as:

\textrm{ERA} = \frac{\textrm{ER}}{\textrm{IP}} \cdot 9

The value that results from this represents the earned runs a pitcher would be expected to allow on average over the course of a standard, 9-inning game. A pitcher who allows 50 earned runs over 120 innings pitched would thus have an ERA of 3.75. This is read as “three seventy-five”.

Wins |W|

A win is awarded to the pitcher who records the last out prior to his team scoring the final go-ahead run in a win. There are also two exceptions to this rule that can (rarely) occur in Major League Baseball games. For the finer details of these occurrences, you can consult official MLB Rule 10.17.

A win functions to indicate which pitcher was most responsible for leading his team to victory. The issue with this is that it only takes into account the results of the game, and not how the defense behind the pitcher played or how his offense performed while batting. As we will see later, there are better ways to quantify a pitcher’s individual performance.

Losses |L|

In much the same way that wins are assigned to pitchers that lead their teams to victory, losses are assigned to a pitcher whose effort leads to his team’s defeat. A pitcher is awarded the loss if he is responsible for the runner that scored the final go-ahead run in a game his team lost. This means that if “Adam” allows a batter to reach base and that batter (regardless of whether or not pitcher Adam is pitching at the time) scores the run that ultimately wins the game for his team, Adam is assigned the loss. It is thus possible for Adam to receive the loss in a game after he has exited the game for pitcher Ben, Carlos, et al. to enter. For example, Ben (or Carlos, and so on) can throw the actual pitch that leads to the runner scoring, but if Adam was responsible for allowing the runner to reach base, then he is still responsible for the loss. In the event that Adam’s team either ties the game or takes the lead, he is no longer “on-the-hook” for the loss, and the decision for the game is reset.

Losses serve to indicate which pitcher is responsible for losing the game for his team but fail to take into account how the team around him played and other outside factors. We will examine better ways to recognize a poor performance later.

Win-Loss Record |W-L|

Plainly, this is the ratio of a given pitcher’s wins-to-losses. This statistic can be given over any time frame (either a series of games, a season, career, etc.). For example, a pitcher who has 12 wins in a year and 10 losses is said to have a record of 12-10. This is read as “twelve and ten”.

Win-Loss Percentage |W-L %|

Similar to the win-loss record, this is the percentage of games a given pitcher wins over the total number of decisions (equal to wins + losses) he is involved in, given to three decimal points. Thus, the same pitcher that is 12-10 in a season has a win-loss percentage of 0.545 (12 wins divided by 22 decisions). This is read as “five forty-five”.

Complete Game |CG|

This statistic represents the number of games in which a pitcher throws every pitch for his team during a given game.

Shutout |SHO|

A shutout is a complete game in which the pitcher also does not allow an earned run. Thus, a starting pitcher who earns a shutout also earns a complete game.

Save |S or SV|

Saves are awarded to a relief pitcher on the winning team under certain circumstances. These are:

  1. The pitcher must finish the game for the winning team (i.e. appear in relief and be responsible for the final out)
  2. The pitcher has not received the win for his team
  3. The pitcher is responsible for at least one out (i.e. pitched 1/3 of an inning)
  4. Lastly the pitcher must meet one of below criterion:
    • Enters the game with a 3-run lead or less and pitches at least one inning
    • Enters the game with the tying run on base, at bat, or on deck
    • Pitches for at least 3 innings

Saves are frequently earned by one specific relief pitcher, termed the closer. In other instances, a different relief pitcher will be tasked with earning the save due to unavailability (because of injury, fatigue, etc.) of the closer.

Taking a Lead: Sabermetric Pitching Stats

With this knowledge, an understanding of the game, and the Basic Hitter Statistics, begin investigating the Advanced Pitcher Statistics. Learning the finer points of advanced statistics will enable a greater enjoyment of the game. Advanced statistics allow to better recognize individual performances that are having the greatest effect on a team’s results. This allows for increased ability in evaluating a player’s performance, discussing the effectiveness of managerial choices and front office competence, and predicting the actions of a team both in-game and off the field. Many teams now rely on metrics the same or similar to those presented on this site in making their decisions.