Aging of Starting Pitchers: 5.4 vs 6.5 Innings - A Comparison of 2019 and 1965

The art of starting in Major League Baseball has undergone a significant transformation over the past few decades. While in 1965 starting pitchers were expected to pitch significantly deeper into games, modern baseball sees an average of just 5.4 innings per start for starters in 2019. This shift reflects a broader trend in baseball strategy and player management.

Role of Relief Pitchers and Bullpen Specialization

One of the key factors behind the decrease in starting pitch duration is the increased reliance on the bullpen and the specialization of relief pitchers. Starting pitcher workloads have become more precarious due to the rise of the bullpen, allowing teams to utilize a greater number of starting pitchers throughout the season. This aligns with the observation that 43 pitchers started 30 or more games in 2022, with 4 pitchers starting 33 games.

Historical Context: 1965

In 1965, the landscape was different. Starting pitchers typically pitched much deeper into games, averaging about 6.5 to 7 innings per start. This era is often viewed with nostalgia, as it included fewer relief pitchers and a greater reliance on starters to complete games. Despite the lower number of teams (20 vs. 30 today), 48 pitchers started 30 or more games, with 2 pitchers starting 42 games. Furthermore, 2 pitchers threw more than 300 innings, and 42 pitchers recorded more than 200 innings. Starting pitchers worked closer to 6.28 innings on average, with relievers pitching 2.7 innings.

Modern Baseball

Contemporary baseball sees pitchers averaging only 1 more inning than their 1965 counterparts, but with a greater number of starts. In 2019, 3672 games were started, with starters averaging 5.26 innings, while relievers reached 3.66 innings. This suggests a mix of long and short starts, indicating a dynamic strategy that maximizes pitcher longevity. The average of 5.4 innings for starters in 2019 is well within the expected range of 5 to 6 innings.

Conclusion and Reflection

The decline in starting pitcher innings from 6.5 to 5.4 innings has been a gradual process influenced by strategic shifts in player usage and team management. While the specific numbers might vary, the general trend toward more relief pitchers and a more complicated rotation schedule is clear. As baseball continues to evolve, the role of the starting pitcher is likely to remain pivotal yet more nuanced.

Note: If you notice a discrepancy in your calculations, it may be worth double-checking the data sources or methodology.