I think that gets to the whole, really good player for a really long time vs. incredible player over a short period of time argument.
For example, who, between these two pitchers, was the "greatest"? (I am deliberately not defining that term) - Pedro Martinez or Greg Maddux?
The case for Maddux:
- Maddux had far better counting stats: 355 w vs. 219 w; 5008.1 ip vs. 2827.1 ip; 3371 k vs. 3154 k, etc.
- Maddux won 4 CYAs vs. 3 for Pedro
- 104.6 bWAR vs. 86.0 bWAR
- 23 seasons vs. 18 seasons
The case for Pedro:
- His rate stats were better: .687 win percentage vs. .610; 2.93 era vs. 3.16; 154 era+ vs. 132; 1.05 whip vs. 1.14; 10.0 k/9 vs. 6.1
- His peak 7-year stretch from 1997-2003 was far better than Maddux' peak 7-year stretch from 1992-1998:
**Pedro: 118-36 (.766), 2.20 era, 213 era+, 0.94 whip, 11.3 k/9, 57.2 bWAR
**Maddux: 127-53 (.706), 2.15 era, 190 era+, 0.97 whip, 6.9 k/9, 54.6 bWAR
- Best single season, Pedro was better:
**Pedro (2000): 18-6, 1.74 era, 291 era+, 284 k, 0.74 whip, 11.8 k/9, 11.7 bWAR
**Maddux (1995): 19-2, 1.63 era, 260 era+, 181 k, 0.81 whip, 7.8 k/9, 9.7 bWAR (so Pedro's best season was 2 wins better than Maddux')
So Maddux was better for longer (and obviously his prime was still insanely good, so he's not really in the category of "really good for a long time"; he was *GREAT* for a really long time), but at their very best, Pedro was simply better than Maddux was, and not simply for a single year, but rather for a long 7-year stretch.
So who was the greater pitcher? It's really hard to say, because there's a lot to be said for either guy, each bringing his own strengths to the table. Give me Pedro in any one-game situation, but Maddux might be the guy if you are building a franchise and saying, we want one guy's entire career.