At the age of 44 and after 20 seasons in Major League Baseball, Jason Giambi announced yesterday that he was retiring from baseball.

From 1995 to 2014, Giambi played with the Athletics, Yankees, Rockies, and Indians. While his last six seasons in the Majors have been somewhat forgettable, there was a time when he was one of the most feared hitters in the game.

Excluding the 2004 season where he spent much of the season sidelined dealing with a benign tumor, from 1999 to 2006 he never hit fewer than 32 home runs, never had an on base percentage below .410, and only once failed to reach more than 100 runs batted in. His average year during that seven season stretch was a .299 average with 38 home runs and 116 runs batted in.

He'll retire with 2,010 hits, 1,441 runs batted in, 440 home runs, a .277 batting average, and a .399 OBP in 2,260 games. He ranks 32nd all time in bases on balls, 41st in homers, 50th in OPS, 54th in on-base percentage, and 62nd in runs batted in. He also finishes with an all time Jaffe WAR Score (JAWS) of 50.8 which ranks 23rd best at the position - though the average for a Hall of Fame first basemen is 65.9.

Never having won a World Series and drawing similar numbers to Mike Piazza in four more years at a less demanding position, it's unlikely Jason Giambi will ever be considered for the Hall of Fame. (For reference, in 20 seasons, Giambi loses significantly in batting average while only having 13 home runs and 106 RBI more than Piazza.) Whereas the mere "possibility" of Piazza doing steroids seems to be what’s been holding him out for the third straight year, Giambi is at a greater disadvantage having admitted to using performance enhancing drugs in 2007.

Without delving any deeper into the controversy surrounding his legacy, let's take a look at how his numbers compare historically to some of the best first basemen to play the game.

The following list is compiled of all non-Hall-of-Fame first basemen who rank higher than Giambi in terms of JAWs, and then the two current first-basemen who rank closest.

If you look closely, you'll see he ranks seventh in home runs, sixth in RBI, seventh in runs, and fifth in OBP. While obviously not Hall-of-Fame numbers, he holds his own with some of the best hitting first basemen to play the game.

There were a few things that surprised me when looking at these numbers. First, although David Ortiz tops Giambi in every stat (save on base percentage and stolen bases), he ranks significantly lower in JAWS. This is likely due to Ortiz having spent more time in the designated hitter position and for having a lower seven-year peak WAR than Giambi.

One more surprise was in two personal favorites of mine, Keith Hernandez and John Olerud, edging him out in JAWS, despite the significantly weaker power numbers. A major reason they graded out higher is because Hernandez and Olerud are widely considered two of the best defensive first basemen of all time. Olerud is fourth all time in total zone runs (TZ), a defensive statistic used to account for how many runs a player saved defensively, with 97. Hernandez has 11 career Gold Gloves, is third all time in assists, and first all time in total zone runs with 120. To put that in perspective, Jason Giambi has a career TZ of -40.

Since his numbers fall short of confirmed steroid users not in the Hall (Rafael Palmeiro, Mark McGwire) and suspected user (Jeff Bagwell), it's unlikely Jason Giambi will ever wind up in Cooperstown. Still, there's no doubting his numbers rank among the best.