Saitama Seibu 's left and right starting pitchers are both ranked high in ERA rankings.

　Saitama Seibu 's two starter pitcher have been pitch impressively, pitcher Tatsuya Imai​ ​Chihiro Sumida at 0.51, ERA ERA the league, and Tomoichiro Sumida at 0.98. Both pitcher have been key players in the starting lineup and have supported the team in recent years, but this season they may make even greater strides.

This time, we will analyze the characteristics and strengths of pitcher Imai and pitcher based on the annual indicators they have recorded. We will look back on the growth trajectory of both pitcher and see in what areas they have improved this season.

(*The following results are as of the end of the match on May 7th)

In addition to improving strike out rate, he has also made notable improvements to his control, which was an issue for him.

The annual indicators that pitcher Imai has recorded so far are as follows.

His career strike out rate is 8.23, which is high for starter, and his ability to get outs on his own is a major strength. However, in the four seasons from 2018, when he made his first-team debut, to 2021, strike out rate was in the sevens or lower, showing a different trend in the early part of his career than it is now.

Since 2022, he has recorded strike out rate of 8 or higher for four consecutive years, and in 2022 and 2024, he recorded more strike out than innings pitched. In 2024, he also won his first title for most strike out, showing that his strike out ability has improved significantly in recent years.

In addition, BB rate was poor at 4.66, and since 2018, BB rate has been in the fours or higher for six consecutive years, making his control unstable and a weakness. However, in 2024, he recorded BB rate of 3.63, the first time in his career that it was in the threes, and in 2025, it was 2.93, an improvement over the previous year. The improvement in his control, which was his biggest issue, is also directly linked to the dramatic increase in the stability of pitch.

As a result, the "K/BB" indicator, which is the number of struck out divided by Walk, has also shown improvement in recent years. From 2018 to 2022, his K/BB was always in the single digits, but in 2023 it was 2.13, and in 2024 it was 2.67, gradually improving. And in 2025, his K/BB will reach the three digits for the first time, showing that his ability as pitcher is steadily improving.

His BABIP this season is very low, but looking at last season's numbers and other stats...

Imai's Avg pitcher in 2025 is a very low .130, well below his career average of .221. Furthermore, in the last four years, he has had three seasons in which he recorded Avg in the single digits, meaning that he has been hit less and less. As a result, his "WHIP" (average number of runner allowed per inning) this season is 0.76, and he has been pitching a dominant style pitch which he rarely allows runner to run.

However, his "BABIP allowed," which indicates the percentage of batted balls in play that became hit excluding Home Run runs, was very low at .168 this season, and his career average was .265, below the general standard of .300. However, it is also worth noting that although his BABIP allowed in 2024 was .281, which was worse than his career average, he had a season that could be called the best of his career that year.

BABIP allowed is said to be an indicator that is easily influenced by luck, but the reason for this is that it is not affected by factors that pitcher can control, such as strike out and BB. In other words, in the case of pitcher Imai, who has a high number strike out and has steadily reduced BB, it is not at all unlikely that he will be able to achieve good results without being greatly influenced by fluctuations in BABIP allowed, as he did in 2024.

He has outstanding control and a certain strike out rate. His ability as pitcher is well-known.

Next, let's take a look at the annual indicators that pitcher Sumida has recorded so far.

His career BB rate is 2.32, which is an excellent level for starter. In his first year as a professional in 2022, BB rate was 3.31, but in 2023 it was 2.82, and in 2024 it was 1.76, improving each year. And this season, BB rate is an astonishing 1.15, which shows that his outstanding control is a major weapon.

In addition, his career average strike out rate is 8.12, which is quite high for starter. As a result, his career average K/BB is 3.50, which is generally considered to be an excellent level. Furthermore, his K/BB has improved every year along with BB rate, reaching 4.40 in 2024 and 6.80 in 2025, indicating that he has very good abilities as pitcher.

In the past seasons, he has not had much luck, but that is changing this season.

Looking at BABIP allowed, Sumida's pitcher average is .303, which is above the generally accepted standard. This suggests that he was a little unlucky in the past seasons, but it is interesting to note that his BABIP allowed in 2024 is .291 and in 2025 is .257, both of which are below the standard in the most recent two years.

As a result, Avg in 2025 will be .203, well below his career average (.248), and his WHIP will be 0.85, the first time it has fallen into the single digits. Given his high ability in areas that pitcher can control, such as strike out rate and BB rate, this season, in which his BABIP is improving in a way that is similar to a rebound from the past, could very well be the year he makes his biggest breakthrough yet.

Both pitcher have strike out power and control, so will they continue to evolve in the future?

Imai is a genuine right-handed pitcher overwhelms hitter with his excellent strike out ability, while Sumida is a left-handed pitcher with outstanding stability who uses his unparalleled control to set up pitch. Although they are different types of pitcher pitcher they both have excellent indicators of the areas they can control.

If both pitcher, who have been pitching well, can continue to achieve double-digit win, it will be pitcher third consecutive year and Sumida pitcher first. Both pitcher, who continue to steadily improve as pitcher, will be able to continue pitch stably after May and lead the team to a higher ranking as a pair of left and right wheels. These two excellent pitcher support the Lions have also shown ample potential to win pitcher titles, so keep an eye on them in the future.

Written by Ryota Mochizuki