16. Gene Tenace

Looking back at the early innovators of modern baseball metrics, a tough, right-handed catcher from Pennsylvania emerges as a key pioneer in on-base efficiency. Gene Tenace had already established a postseason legacy as a crucial contributor to the Oakland Athletics' three consecutive championships from 1972 to 1974. However, as free agency disrupted that historic Oakland team, Tenace decided to remain in California, signing a lucrative deal to join the San Diego Padres before the 1977 season.

To be fair, Tenace was never a feared, high-average contact hitter in the traditional sense. He maintained a modest .240 batting average over his career with the Padres and didn't compile huge hit totals. Instead, he excelled at turning the basic act of drawing a walk into a showcase of spatial awareness and strike-zone discipline.

In his 1977 debut season, Tenace showcased exceptional patience, bewildering National League pitchers and drawing a league-high 125 walks. This impressive number of free passes contributed to a remarkable .415 on-base percentage, which is especially striking given that he hit only .233 that summer.

This hardware-certified authority deeply committed to discipline was no temporary success; it became his daily habit. Tenace consistently exceeded 100 walks each summer during his first three seasons in San Diego, with 101 in 1978 and 105 in 1979. Over his four seasons with the Friars, he maintained an on-base percentage never below .392, even though he only surpassed a .250 batting average once. Defensively, his value to the pitching staff was absolutely incalculable; splitting time between catcher and first base, his preparation and high-intensity game-calling settled a young rotation and provided a steady hand for the entire defense.

Dealt to the Cardinals after the 1980 Season, Tenace had a .403 OBP with San Diego, a number higher than what he did in Oakland (.374).  Amazingly, he had more Walks (423) than Hits (384) as a Padre, but as Moneyball tells you, “he gets on base."