Sport Rulebook

Understanding FIP and Its Limitations in Evaluating Pitchers

Understanding FIP in Baseball

Baseball is a sport that demands precision and strategy, both for hitters and pitchers. Pitchers, in particular, have a variety of metrics and statistics to measure their performance, with one of the most significant being FIP.

In this article, we will explore the concept of FIP in depth, understanding what it is, why it’s used, and how we can evaluate pitchers using this statistic. What is FIP?

Fielding Independent Pitching (FIP) is an advanced statistic used to evaluate a pitcher’s performance by taking into account only those things that the pitcher can control. These include strikeouts, walks, and home runs.

FIP measures a pitcher’s effectiveness in terms of preventing the three true outcomes, namely strikeouts, walks, and home runs, which are the biggest determinants of a pitcher’s success. FIP is used as a tool to determine the pitching metrics of a player where the impact of other factors such as fielding is beyond control.

The FIP metric’s fundamental point is that pitchers can not control the number of hits that fall among their defense. It eliminates the effect of bad fielding on a pitcher’s ERA, allowing for more accurate comparisons between pitchers.

Why is FIP Used? FIP plays a vital role in the analysis of a pitcher’s performance as it helps to separate pitching effectiveness from defensive performance.

It provides a clearer picture of how good a pitcher is eradicated from the luck factor that influences defense. Several factors affect a pitcher’s ERA, some of which are beyond their control.

Fielders’ errors, bad luck, and good luck from the opposing team can influence whether or not a pitcher gives up a hit, meaning that ERA is not always an accurate reflection of a pitcher’s effectiveness.

FIP takes into account only those factors that the pitcher can control, making it a useful metric to determine the quality of a pitcher’s performance.

Furthermore, FIP also accounts for leaguewide pitching conditions and avoids making decisions based on park effects. How Do You Calculate FIP?

FIP is calculated using a basic equation:

FIP = ((13 x HR) + (3 x BB) – (2 x K)) / IP + league constant

The league constant is derived by dividing the league’s total earned runs allowed by the total number of innings pitched. For 2021 as an example, the league constant is 3.776.

The variables in the equation are multipliers that emphasize the importance of certain variables over others. As an example, a home run counts against a pitcher more than a walk, emphasizing the lack of control a pitcher has over allowing home runs.

Let’s take a look at a recent example to better understand FIP. In 2020, the New York Mets Jacob deGrom had a 2.38 ERA but a 1.67 FIP.

DeGroms ERA may have suggested he was one of the best pitchers in the league, but his FIP was an indication that he was even better. He had the lowest FIP of the past decade.

FIP takes into account deGrom’s impressive strikeout rate, which was more than 13 K/9 innings, and his low walk and home run rates. By eliminating the impact of his fielders, FIP can show how dominant deGrom was in the league that year.

Evaluating Pitchers with FIP

FIP ratings can vary from season to season for pitchers. A good FIP score is considered to be around 3.70, which is close to the average FIP score for pitchers in the league.

Pitchers with FIP ratings of around 3.00 or lower are considered exceptional. Evaluating a pitcher’s FIP performance requires considering how FIP ranks against his ERA.

If the difference between a player’s FIP and ERA is significant, then it’s a good indication that defense threw off their ERA numbers. On the other hand, those whose ERA is lower than their FIP could suggest that they were lucky, deriving benefits from their defense.

Several factors can impact FIP scores, such as small ballparks, park factors, and pitcher-friendly ballparks. This is where xFIP comes in.

What Is xFIP? Expected Fielding Independent Pitching (xFIP) is another metric that is related to FIP but considers a pitcher’s home run to fly ball rate (HR/FB), an important variable in determining the number of home runs a pitcher allows in a relatively stable environment, such as a neutral ballpark.

Some pitchers may perform worse in their home ballpark because of the stadium’s dimensions, which give the home team a defensive advantage. These types of ballparks are called pitcher-friendly ballparks, and xFIP can help mitigate their effect on a pitcher’s overall performance.

What Is FIP-? FIP Minus (FIP-) is yet another metric that is related to FIP but also takes into account park factors that can affect a pitcher’s performance.

By removing park factors, we can compare pitchers who play in different ballparks in terms of their adjusted statistical performance. FIP- is measured on an ERA+ scale, and a score of 100 is a league average.

Anything over 100 means the pitcher is above average, and anything below 100 means the pitcher is below average. For instance, if a pitcher has an FIP- of 90, they are 10% above the league average in terms of run prevention.


FIP is a metric used to evaluate a pitcher’s performance, which eliminates the effect of luck and defense from the equation. This statistic is essential to differentiate individual performances and remove the influence of certain external factors that might make up a pitcher’s ERA.

Evaluating a pitcher’s quality involves considering the difference between FIP and ERA, along with multiple other metrics like xFIP and FIP-. Together, these tools help to give us a more comprehensive picture of a pitcher’s performance.

Limitations of FIP

While FIP is an important metric used to evaluate a pitcher’s performance, it does have its limitations. In this article, we will explore some of the limitations of FIP, including how FIP compares to other pitching metrics, and its inconsistencies in capturing certain types of pitchers.

FIP Vs. Other Pitching Metrics

One of the limitations of FIP lies in how it compares to other pitching metrics, such as Earned Run Average (ERA). While FIP accounts for strikeouts, walks, and home runs, ERA considers all types of hits, whether they are hit weakly or hard.

This means that pitchers who induce weak contact, as opposed to strikeouts, may have a lower ERA than FIP might suggest. Take Mariano Rivera, for example.

Rivera is one of the most dominant relievers in baseball history but has a career FIP of 2.76, which is much higher than his career ERA of 2.21. This is because Rivera was a master of inducing weak contact and getting batters to hit ground balls, which are better for preventing runs than strikeouts.

Similarly, Kyle Hendricks, a pitcher for the Chicago Cubs, does not get many strikeouts but consistently pitches well in terms of ERA despite his high FIP. Hendricks relies on inducing weak contact to get outs, and while FIP doesn’t account for weak contact, his ERA shows how effective this strategy can be.

Another pitcher who defied FIP is John Burkett. Burkett pitched from 1987 to 2003 and was known for his low walk rate and opposition to strikeouts.

Burkett relied on great defensive support from his teammates and would pitch-to-contact, allowing his defenders to make outs instead of striking out batters. However, Burkett’s career FIP was higher than his career ERA by almost half a run.

Inconsistencies in FIP

Another limitation with FIP is its inability to capture certain types of pitchers. FIP favors pitchers who get strikeouts and prevent home runs, which means that it overlooks some pitchers who might have different strengths.

Some pitchers might pitch to contact and induce ground balls, having a lower strikeout rate than other pitchers. Furthermore, FIP is not entirely accurate in evaluating pitchers who depend on generating weak contact, such as Rivera and Hendricks.

It doesn’t account for the quality of the balls struck into play and assumes that all balls hit into play have equal weight.

Moreover, while FIP is an excellent tool for examining pitchers who have consistently strong performances over a season, it can’t capture fluctuations.

Pitchers who go through a rough patch can expect to have higher FIPs than usual. For example, during the shortened 2020 season, pitchers had fewer opportunities to even out their FIP over a more extended period, meaning FIP is less helpful in evaluating their 2020 performance.

FIP can also be subject to pitcher types. For example, hard-throwing relievers who specialize in striking out batters might have higher FIPs than soft-throwing ground-ball specialists.

While both might be equally effective, FIP tends to undervalue the soft-throwing pitcher’s impact.

Overreliance on Strikeouts and Home Runs

FIP gives too much importance to strikeouts and home runs while neglecting other factors such as defensive abilities. This overreliance can make FIP less accurate in evaluating certain pitchers’ performance, such as those who pitch to contact.

For instance, a ground-ball pitcher with good defensive support might not get many strikeouts, and their FIP would not adequately represent their effectiveness. Additionally, FIP can sometimes overemphasize the impact of home runs.

Pitchers with lower home run rates, such as ground-ball and fly-ball pitchers, can be undervalued by FIP because they may not strike out as many batters.


While FIP is an essential tool for evaluating a pitcher’s performance, it does have limitations and inconsistencies. It’s essential to understand its strengths and limitations when evaluating a pitcher’s performance.

ERA is another valuable metric that can provide a glimpse into a pitcher’s effectiveness that FIP might not. By considering all these metrics and situational nuances, we can acquire a fuller appreciation of a pitcher’s performance.

In this article, we explored the limitations of FIP, an important metric used to evaluate a pitcher’s performance. While FIP accounts for strikeouts, walks, and home runs, it does have limitations in terms of evaluating certain types of pitchers, such as ground-ball specialists, and accounting for weak contact.

Nevertheless, FIP remains an effective tool for evaluating most pitchers’ performance and provides a clearer picture of a pitcher’s effectiveness. In conclusion, understanding the strengths and limitations of FIP is crucial in evaluating a pitcher’s performance accurately and comprehensively.


What is FIP?

– FIP stands for Fielding Independent Pitching, which is an advanced statistic used to evaluate a pitcher’s performance by taking into account only those things that the pitcher can control.

What are some of the limitations of FIP?

– FIP has limitations in evaluating certain types of pitchers, such as those who rely on generating weak contact and those who pitch to contact.

How does FIP compare to other pitching metrics?

– FIP is different from other metrics, such as Earned Run Average (ERA) in that it accounts for strikeouts, walks, and home runs, whereas ERA considers all types of hits, whether they are hit weakly or hard.

What is ERA? – ERA stands for Earned Run Average, a statistic in baseball used to evaluate a pitcher’s effectiveness at preventing runs from being scored.

What is the importance of FIP in evaluating pitchers?

– FIP is an essential tool for evaluating a pitcher’s performance by eliminating the effects of luck and defense from the equation.

How can pitchers with high FIP rankings still be effective?

– Pitchers with high FIP rankings can still be effective, such as those who rely on inducing weak contact or pitch-to-contact strategies, as FIP does not account for the quality or type of balls hit into play.

How can FIP be improved?

– FIP can be improved by taking into account other factors that affect a pitcher’s performance, such as defensive abilities and quality of the balls put into play.

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