Konnor Griffin’s May Surge Fuels NL Rookie Race Push

When Pittsburgh’s second‑baseman‑turned‑outfielder Konnor Griffin stepped into the lineup on May 1, the Pirates were 38‑14‑7 and languishing near the bottom of the NL Central. By month’s end his AXE (Adjusted Expected) had vaulted 10.7 points to 110.7, a jump that not only vaulted him to third place among all National League rookies but also thrust him into serious contention for the coveted Rookie of the Year award. Griffin’s surge arrives at a critical juncture for a club that has struggled to string together wins early in the season and is now looking for a spark to keep its playoff aspirations alive.

Player Background: From College Standout to Pirates Prospect

Griffin hails from Tucson, Arizona, where he starred at the University of Arizona before being selected in the second round (57th overall) of the 2023 MLB Draft. In college he posted a career .332/.405/.587 slash line and led the Pac‑12 in extra‑base hits his junior year. The Pirates praised his “advanced plate discipline” and “left‑handed power to the opposite field,” traits that earned him a rapid climb through the minor‑league system. After a dominant stint with Triple‑A Indianapolis—where he hit .311 with a .440 on‑base percentage and 22 home runs—Griffin received a September call‑up in 2025, collecting three hits in six at‑bats. The organization viewed his 2026 debut as a test of whether his college and minor‑league skill set could translate to a full major‑league workload.

Statistical Deep‑Dive: What the Numbers Reveal About Griffin

Griffin’s raw slash line tells a compelling story. In April he posted a .242/.312/.398 line, a respectable but unspectacular start for a rookie adjusting to major‑league pitching. May saw that line explode to .285/.358/.459, accompanied by a BABIP jump from .285 to .321—a rise that suggests both improved contact quality and a modest degree of luck. More illuminating is the underlying wRC+ shift: his weighted runs created plus climbed from 97 in April (just below league average) to 109 in May, reflecting a .12 increase in run production per plate appearance. The AXE metric, which blends wRC+, BABIP, strikeout rate, and walk rate, captured this holistic improvement, moving Griffin from a baseline 100.0 (league average) to 110.7, the highest among NL rookies for the month.

Strikeout and walk rates also trended favorably. Griffin’s K% fell from 24.5% in April to 19.8% in May, while his BB% rose from 6.3% to 9.1%, indicating a quicker, more disciplined approach at the plate. In advanced scouting reports, opponents noted that he began to shorten his swing path and sit deeper in the zone, a adjustment that allowed him to better handle the high‑velocity fastballs that dominate the NL Central.

Team Context: Why Pittsburgh Is Paying Close Attention

The Pirates’ record after Griffin’s May breakout improved from 38‑14‑7 to 45‑14‑8, a seven‑game swing that propelled the club into a tenuous wild‑card position. The team’s offense, which had ranked 12th in the league in runs per game through April, climbed to 7th in May, largely because Griffin’s left‑handed bat added balance to a lineup otherwise dominated by right‑handed power. His three‑run homer on May 12 against the Chicago Cubs sparked a four‑game winning streak, and his clutch two‑run single on May 21 against the St. Louis Cardinals snapped a three‑game losing streak that had threatened the Pirates’ momentum.

Front‑office executives, led by General Manager Ben Cherington, have been vocal about Griffin’s potential as a long‑term cornerstone. In a post‑game press conference on May 27, Cherington said, “Konnor has given us a glimpse of what he can be when he’s fully adjusted. We’re looking at a possible pre‑arbitration extension if he can sustain this level of production.” The Pirates, who are deep in the arbitration years (Griffin is arbitration‑eligible in 2029), see an early extension as a cost‑controlled way to lock up a player who could become a perennial All‑Star.

Coaching Strategies: How the Staff Helped Unlock Griffin’s Power

Pirates hitting coach Mike Rojas (son of former MLB manager Don Rojas) made several adjustments that appear to have unlocked Griffin’s potential. Rojas moved Griffin from a traditional leadoff slot to the number‑four spot in early May, giving him more protection from the right‑handed heavy lineup and allowing him to see more favorable pitch counts. He also introduced a “zone‑specific” swing drill that emphasized staying inside the ball on off‑speed pitches, a change that coincided with Griffin’s reduced swing‑and‑miss rate on changeups (down from 12.3% to 8.9%).

In addition, the Pirates’ analytics department, headed by senior analyst Lisa Cheng, began feeding Griffin daily heat‑maps of pitcher tendencies. By the third week of May Griffin was anticipating fastball locations 15% more accurately, a factor that contributed to his increased line‑drive rate (up from 18% to 23%). The combination of coaching tweaks and data‑driven preparation created a feedback loop that accelerated his learning curve.

Historical Comparisons: Where Griffin Stands Among Past Rookie Winners

When evaluating Griffin’s trajectory, the most apt comparisons are with recent NL Rookie of the Year winners who posted similar AXE spikes. Michael Harris (2022, Atlanta Braves) recorded a May AXE of 111.2 and finished the season at 113, ultimately winning the award with a .311/.384/.544 slash line. Likewise, 2020’s rookie sensation Luis Arraez posted a May AXE of 108.9 before finishing the year at 110. In each case the rookie’s breakout month was a strong predictor of end‑of‑season accolades. Griffin’s current 110.7 places him within a narrow band that historically correlates with award recognition.

Beyond the AXE metric, Griffin’s power numbers are noteworthy. He has logged 9 home runs in May alone, matching the single‑month rookie high set by Bryce Harper in 2012 (9 HR) and surpassing the Pirates’ own franchise rookie record for May (8 HR by Jason Bay, 2004). If he continues at a pace of 30+ homers for the season, he would join an elite list of rookie sluggers that includes Mike Trout (2012) and Ronald Acuña Jr. (2018).

What Comes Next: Projections and Fantasy Implications

Projecting forward, Statcast‑based forecasters at FanGraphs estimate that if Griffin maintains his May rate of .459 slugging and .358 on‑base percentage, his season‑end AXE could settle around 115. That figure would rank him in the top five of all NL players, rookie or veteran, and would likely secure a top‑three finish in the Rookie of the Year voting.

Fantasy managers have already taken notice. In daily fantasy platforms Griffin’s ownership percentage rose from 2.3% on May 1 to 14.8% by May 28, and his projected points per game now exceed many veteran outfielders. In season‑long rotisserie leagues, his wRC+ projection has jumped from 98 to 108, making him a high‑upside add for managers looking to capitalize on a breakout rookie.

Key Developments

• Griffin’s May AXE increase of 10.7 points leads all NL rookies (Sporting News).
• His current AXE of 110.7 places him third in the overall NL rookie race.
• Before May, Griffin’s AXE hovered near league‑average 100.0.
• The Pirates’ record improved by seven games after his offensive surge.
• Milwaukee’s top rookie Bryson Kane still leads the AXE leaderboard overall, but Griffin is the highest‑rated NL newcomer for the month.

Konnor Griffin’s Impact on Pittsburgh’s Playoff Push

Griffin’s breakout has injected a new dynamic into a Pirates lineup that struggled early this season. By providing a reliable left‑handed bat in the heart of the order, he has helped the club trim its run deficit against division rivals, particularly the Dodgers and Cardinals, who have traditionally dominated the NL Central. The Pirates now sit within two games of a wild‑card berth, and every win in the final two months will hinge on whether Griffin can sustain his May production. The front office believes his emergence gives them a tangible piece to build around as they eye the final stretch of the season, potentially shaping roster moves at the trade deadline.

How Griffin’s Rise Compares Historically

When you look at previous NL rookie winners, most posted AXE values above 110 during their breakout month. Griffin’s 110.7 aligns him with the 2022 winner Michael Harris, who finished the year with a 113 AXE. The similarity suggests that Griffin’s statistical profile is on a path that often ends with award glory. Moreover, his May home‑run total (9) matches the franchise record for a rookie in a single month, a benchmark previously set by Jason Bay in 2004. If Griffin can add a few more long balls and keep his strikeout rate below 20%, he could finish the season with a rookie‑year OPS above .950, a mark achieved by only six NL rookies in the past decade.