The series on visualizing Bill James Starting Pitcher Ranks continues with the ten year span starting in 2004 and ending in 2013. The 1984-1993 span represents the Roger Clemens era, as his career started in 1984. The 1994-2003 span represents the Pedro Martinez era, as Martinez fully moved into the role of starting pitcher in 1994. The 2004-2013 era is more difficult to name. It’s probably the Justin Verlander era, but it could just as easily be the Johan Santana or Felix Hernandez or Roy Halladay or CC Sabathia era.

The spreadsheet shows the daily scores for the ten years of any pitcher who occupied the top slot in ranking for at least one day. The graph shows, for the group, how they moved against each other over time.

For the previous decade, only five pitchers obtained the top slot, with the fifth (Curt Schilling) not beating out one of the other four until the very end. The latest stretch saw fourteen different pitchers earn top honors. The era contains a nice mixture of pitchers with long runs of domination, and pitchers who burned brightly for a short time.

There are also a number of instances when a few of these pitchers are grouped very closely around the number one slot. The 2004 season picks up where 2003 ended, with Shilling, Martinez, and Randy Johnson fighting for the top slot, but now joined by Jason Schmidt. Schmidt is one of the pitchers with a bright but short lived burst. He pitched okay for a bad Pirates team in the 1990s, then joined the Giants in 2001 and took his game to another level, greatly increasing his strikeout rate. He reaches the top in July of 2004, then starts to fall and is pretty much done by the start of the 2007 season.

In September 2005, Santana joins the battle with Martinez and Johnson, while Roger Clemens makes his last appearance as the top starter in the game. Clemens reached number one in three decades. Santana would win the battle. Martinez fought Santana for the stop slot in 2006, but the Twins ace would dominate until the 2008 season.

At the end of 2008, two challengers arise to Santana. The Indians trade Sabathia to the Brewers, and Sabathia goes on a tear than nets him a 1.65 ERA in 17 starts. Brandon Webb reaches the pinnacle of his great but too short career. Sabathia and Santana end the season with Santana leading by about 0.3 points.

Santana starts 2009 strong, but by July there is another inflection point. As of the morning of July 8, 2009, Dan Haren sits on top with a small lead over Tim Lincecum and Sabathia, with Santana in fourth place and Halladay in fifth, fifteen points separating the lot. Sabathia and Lincecum would emerge from this scrum as the top two pitchers, Sabathia finishing at the top of the pack that year.

Sabathia and Lincecum continued to go toe-to-toe at the start of 2010, but Roy Halladay zoomed past both. Sabathia caught him briefly, and a great spurt by Hernandez brought King Felix briefly to the top*.

*And now an interlude to explain something that is lacking in my calculation. The rankings as defined by Bill James use post-season data. The Day by Day Database only has post-season data going back to 2002. When I have the data, I use it in the calculations, which is why you might see different numbers if you look at rankings on the Bill James site and Baseball Musings. Most of the time, it doesn’t make a lot of difference in the rankings, but twice it helps Roy Halladay.

At the end of the 2010 regular season, Hernandez holds about a seven point lead over Halladay. Then Halladay throws a no-hitter. Hernandez is not in the playoffs, so his score starts to decay. Halladay pitches decently in two more starts, and stays on top over the winter.

In 2011, Halladay continues to pitch well, but Justin Verlander comes into his own and blows past Halladay in July. Verlander finishes the regular season on top, but pitches poorly in the post-season, while Halladay makes two good starts. Once again Halladay spends the winter on top, interrupting what could have been a straight two years of domination for Verlander.

Verlander’s reign ends on 5/17/2013, when Clayton Kershaw takes over the top slot. As a coincidence, both Verlander’s and Kershaw’s line are colored a shade of yellow. The two have similar rises to the top, but Kershaw’s slope is a bit higher, so he reaches the top quicker.

Pitcher of that decade goes to Santana, who controlled the top from end of 2006 through the end of 2009, and continued to be in the hunt through 2010. I do like that we had three pitchers who were briefly the best, Schmidt, Webb, Haren. There were lots of different pitchers to like and plenty of arguments about who was the best of the bunch.