A slow start for the NBA’s television partners has persisted into midseason.

Since Christmas Day, 31 of the 43 NBA games on ESPN/ABC and TNT that can be compared to last year have had declines in viewership [see chart]. Twenty-five of those games have had double-digit declines, including seven this month alone.

Keep in mind last year was anomalous due to the owners’ lockout. The Christmas Day slate doubled as Opening Day and the shortened season meant a higher concentration of high-quality games on national TV.

Those factors do not explain everything, however. After all, viewership declined for 20 of 33 pre-Christmas games this season — all of which were compared to 2010, as there were no such games in 2011.

Overall, average viewership has declined on each of the NBA broadcast partners this season — by 5% on ABC (6.9M to 6.5M), by 11% on ESPN* (2.0M to 1.8M) and by 24% on TNT^ (2.8M to 2.1M).

First Half NBA Averages on ESPN/ABC and TNT

Net 2012 2011 vs. ’11 TCs Dates Viewers TCs Dates Viewers TNT 32 10/30/12-2/14/13 2.1M 25 12/25/11-2/23/12 2.8M -24% ESPN 47 11/2/12-2/10/13 1.8M 30 12/25/11-2/22/12 2.0M -11% ABC 6 12/25/12-2/10/13 6.5M 6 12/25/11-2/19/12 6.9M -5%

Pre-Christmas numbers available here. Date Time (ET) Away Home Net Viewership 2012 2011 vs. ’11 Tue., 12/25/12 12:00 PM Celtics Nets ESPN 3.7M 5.9M -36% 3:00 PM Knicks Lakers ABC 8.8M 9.0M -3% 5:30 PM Thunder Heat ABC 9.6M 11.0M -13% 8:00 PM Rockets Bulls ESPN 2.4M 2.6M -7% 10:30 PM Nuggets Clippers ESPN 2.3M 3.0M -23% Thu., 12/27/12 8:00 PM Mavs Thunder TNT 2.2M 2.4M -8% 10:30 PM Celtics Clippers TNT 2.3M 3.3M -32% Fri., 1/4/13 8:00 PM Bulls Heat ESPN 1.8M 1.8M 2% 10:30 PM Lakers Clippers ESPN 3.1M 1.3M 139% Wed., 1/9/13 8:00 PM Lakers Spurs ESPN 2.0M 2.5M -18% 10:30 PM Mavs Clippers ESPN 1.8M 3.5M -49% Thu., 1/10/13 8:00 PM Knicks Pacers TNT 1.5M 1.7M -16% 10:30 PM Heat Blazers TNT 1.4M 1.5M -7% Fri., 1/11/13 8:00 PM Bulls Knicks ESPN 1.9M 2.5M -23% 10:30 PM Thunder Lakers ESPN 2.3M 2.7M -16% Wed., 1/16/13 8:00 PM Rockets Mavs ESPN 1.4M 1.3M 10% 10:30 PM Heat Warriors ESPN 1.7M 2.1M -22% Thu., 1/17/13 8:00 PM Clippers T’Wolves TNT 1.7M 4.4M -62% 10:30 PM Heat Lakers TNT 3.5M 2.0M 81% Fri., 1/18/13 8:00 PM Bulls Celtics ESPN 2.0M 2.0M -2% 10:30 PM Thunder Mavs ESPN 2.2M 2.2M -1% Mon., 1/21/13 1:00 PM Pacers Grizzlies ESPN 0.8M 0.9M -18% 7:00 PM Spurs Sixers TNT 1.3M 2.4M -43% 9:30 PM Lakers Bulls TNT 2.2M 3.1M -27% Thu., 1/24/13 8:00 PM Knicks Celtics TNT 2.5M 1.6M 51% 10:30 PM Clippers Suns TNT 1.4M 1.7M -16% Fri., 1/25/13 8:00 PM Spurs Mavs ESPN 1.1M 2.3M -51% Sun., 1/27/13 1:00 PM Heat Celtics ABC 4.6M no game 3:30 PM Thunder Lakers ABC 6.3M 5.7M 11% 6:30 PM Hawks Knicks ESPN 1.5M 1.4M 10% Wed., 1/30/13 8:00 PM Heat Nets ESPN 2.0M 1.9M 6% 10:30 PM Lakers Suns ESPN 2.4M 2.0M 19% Thu., 1/31/13 8:00 PM Grizzlies Thunder TNT 1.6M 2.3M -31% 10:30 PM Mavs Warriors TNT 1.2M 1.9M -37% Fri., 2/1/13 7:00 PM Heat Pacers ESPN 1.6M 2.2M -25% 9:30 PM Lakers T’Wolves ESPN 2.0M 2.5M -20% Wed., 2/6/13 9:00 PM Spurs T’Wolves ESPN 1.1M no game Thu., 2/7/13 8:00 PM Lakers Celtics TNT 2.6M 3.1M -16% 10:30 PM Bulls Nuggets TNT 1.3M 1.9M -32% Fri., 2/8/13 8:00 PM Clippers Heat ESPN 1.9M 3.0M -36% 10:30 PM Bulls Jazz ESPN 1.5M 2.1M -29% Sun., 2/10/13 1:00 PM Clippers Knicks ABC 3.3M no game 3:30 PM Lakers Heat ABC 6.5M 4.1M 59% 8:00 PM Spurs Nets ESPN 1.3M 2.2M -39% Thu., 2/14/13 8:00 PM Heat Thunder TNT 3.4M 2.4M 40% 10:30 PM Clippers Lakers TNT 2.6M 1.7M 51%

* Last year’s ESPN average is an unofficial approximation.

^ This year’s TNT average is an unofficial approximation.