# James Harden and TPA: a match made in statistical heaven

Basketball statistics have had a boom as of late. It seems as if every year or two, there is a brand-new stat to “revolutionize” the way the sports community digests basketball. Additionally, different sources will harp on different statistics. Inpredictable.com uses winning percentage added (WPA), FiveThirtyEight uses Wins Above Replacement (WAR; a common baseball statistic retroactively fitted for basketball consumption), and multiple other websites  offer different ways of thinking about basketball. Thus, it’s very easy–especially for the writer of this current article–to sometimes get too caught up.

NBAmath.com strives for a simple(r) approach with the statistic Total Points Added (TPA). In layman’s terms, Total Points Added (TPA) is offensive impact minus defensive impact.

OPA is derived by adjusting offensive box plus/minus (OBPM) to account for the number of possessions the player in question is present for. Similarly, DPS is derived from a similar adjustment of defensive box plus/minus (DBPM) with that same number of possessions. OBPM and DBPM, both calculated by http://www.basketball-reference.com/about/bpm.html estimate the per-100-possessions value of a player on either end of the court. Add OPA and DPS together, and you have TPA. A score of zero indicates that a player was perfectly average (by no means a bad thing for rookies or lifelong end-of-bench players), while anything positive means they were better than an average-level replacement.

nbamath.com

As has been stated multiple times on this website and elsewhere, James Harden has been on a tear of historic proportions. This can be seen in basic box score statistics as his scoring is up there with the likes of prime Michael Jordan and Kobe Bryant. In the TPA world, Harden has also cemented himself as a one of a kind player having a one of a kind season.

As an illustration, below is a graph depicting where current NBA players stand on their TPA value at this point in the season. Notice any player that stands out?

Clearly, James Harden is on an island. As of  January 13, 2019, James Harden leads the NBA in TPA by a lot, at 345.23, which is 56.99 greater than the second ranked player, Anthony Davis (288.24). If Harden continues on this stretch exactly as he did during the first part of the season, he will end up having the 12th highest TPA in a single season since 1980 and the highest in Rockets history.

Offensively, Harden has an Offensive Points Added (OPA) of 324.40, which is first in the league by far with second being more than 100 points less. If he continues on the same exact pace throughout the second half of the season, Harden would end up as having the ninth highest single season OPA of all time.

Historically, James Harden is 27th all-time in NBA history with a cumulative TPA of 3519. This is higher than Kevin Durant, Steph Curry and Paul Pierce.

While it’s unlikely that James Harden is able to keep up his current stretch of dominance through the entire season, one thing we know for certain is that if he is able to continue at even 75%, he will have one of the greatest individual seasons of all time.

About the author: David Allen is a third year medical student at Ohio State University College of Medicine specializing in Surgery. You can find his selections of Rockets film at RocketsFilm on imgur. David’s favorite Rockets are: TMac, Trevor Ariza, and Steve Francis. Twitter: @DavidZAllen614.