Reverse lineup protection: Chandler Simpson’s impact on Junior Caminero

Q: How does Chandler Simpson impact Junior Caminero's performance?

Chandler Simpson's presence on first base leads to Junior Caminero seeing fewer fastballs, but it also results in improved swing decisions and contact rates for Caminero.

Q: What are the fastball percentages for Junior Caminero with Simpson on first base?

When Chandler Simpson is on first base, Junior Caminero sees only 37.9% fastballs, compared to 42.0% overall.

Q: What is the significance of lineup protection in baseball?

Lineup protection suggests that a hitter performs better when a strong hitter bats behind them, as pitchers are less likely to pitch around them.

Q: How does Junior Caminero's performance compare with Yandy Diaz on first base?

Caminero sees even fewer fastballs with Yandy Diaz on first base (31.1%) compared to when Simpson is on first, but his performance is negatively impacted by Diaz's lack of running threat.

ST PETERSBURG, FLORIDA - APRIL 06: Chandler Simpson #14 of the Tampa Bay Rays looks to run during a game against the Chicago Cubs at Tropicana Field on April 06, 2026 in St Petersburg, Florida. (Photo by Julio Aguilar/Getty Images) | Getty Images *Thanks to Ian Malinowski and Adam Sanford in our Slack channel for suggesting that Chandler Simpson may be getting more pitches to run on when Junior Caminero is at the plate*. Lineup protection is the idea that a hitter performs better when a strong hitter bats directly behind them in the lineup. The theory is that pitchers will be less willing to pitch around or intentionally avoid the first hitter because they don’t want to face another dangerous bat with runners on base. While research generally suggests lineup protection has only marginal effects, something different may be happening with Junior Caminero when Chandler Simpson is on first base. Surprisingly, Caminero is actually seeing *fewer* fastballs and appears to be getting pitched around more often in those situations. This may not necessarily be a bad thing; Caminero appears to ““level up” in these situations. Below are the rates at which hitters have seen four and two-seam fastballs since 2025:

League average all situations: 47.2%
League average with just runners on first base: 48.0% League-wide, the presence of a runner on first base has almost no effect on fastball usage. This trend is also evident when we look at the break-down per team: There are a few base runners who break this trend, but none to the extent that Chandler Simpson changes things. Rays hitters see 47.9% of fastballs overall and 47.3% with just a runner on first base, but that number jumps to 54.4% when that runner on first base is Simpson. Breaking this down on an individual hitter level (min. 15 pitches seen with just Simpson on first base) reveals something really interesting: | | | | | --- | --- | --- | | Hitter | Fastball% Overall | Fastball% Simpson on First Base | | | 49.5% | 63.0% | | | 42.3% | 60.6% | | Junior Caminero | 42.0% | 37.9% | | | 50.9% | 61.1% | | | 51.0% | 52.9% | | | 46.2% | 47.1% | The most surprising result belongs to Caminero: he actually sees *fewer* fastballs when Simpson is on first base. The average in-zone rate for four and two-seam fastballs is typically at or above 55% each season while breaking balls and offspeed pitches are typically under 43%. Caminero has hit directly behind Simpson in 19 of 36 games this season, including 18 of the last 24 games. Why would the Rays want their best power hitter seeing fewer pitches in-zone? One possible explanation is avoiding double plays, but the early results don’t strongly support that idea. Caminero’s double-play rate actually increases with Simpson on first base, though the sample remains very small. While the results aren’t there yet in this small sample, Caminero appears to be more disciplined and controlled in these situations. He makes better swing decisions (evident in his zone minus out-of-zone swing rate) and more contact when just Simpson is on first base: | | | | | --- | --- | --- | | | Overall (1021 PA) | Just Simpson on first base (22 PA) | | Z-O Swing% | 39.1% | 47.8% | | Contact% | 76.0% | 82.6% | This is an interesting trend; Caminero is seeing fewer fastballs but his approach is significantly better in these scenarios. Through his first 22 PAs, Caminero has an uninspiring .208 wOBA – much lower than the .357 mark he has maintained in his career so far. An improved process *should* translate into even better production in a larger sample considering he already has 80-grade power. The potential for greater production from Caminero with Simpson on first could explain why the Rays are comfortable with the trade-off in production from the leadoff spot by having Simpson there instead of Yandy. Caminero actually sees even fewer fastballs with Yandy on first than Simspon, but that doesn’t benefit Yandy in the same way it benefits Simpson because Yandy isn’t a threat to run: | | | | | | --- | --- | --- | --- | | | Overall (1021 PA) | Just Yandy on first base (45 PA) | Just Simpson on first base (22 PA) | | Fastball% | 42.0% | 31.1% | 37.9% | | Z-O Swing% | 39.1% | 32.9% | 47.8% | | Contact% | 76.0% | 75.9% | 82.6% | | wOBA | .357 | .324 | .208 | There are two key things to monitor going forward: whether Caminero’s improved process with Simpson on base holds over a larger sample, and whether that process eventually translates into better production. The Rays already know Díaz is the more productive leadoff option, but Simpson’s ability to pressure defenses and alter pitch selection may create indirect benefits elsewhere in the lineup – particularly in elevating Caminero to another level. If those effects continue to improve Caminero’s underlying process, the trade-off could become worthwhile.