(S2 is Season 2, S3 is Season 3)
na is North America, eu is Europe, kr is Korea, cn is China, sea is South-East Asia.
Total players that placed in the 1v1 gametype, and players that placed in any ladder gametype.
1V1 PLAYERS ALL PLAYERS
S2 S3 % diff S2 S3 % diff
na 428,201 381,855 (89.2%) 597,561 551,524 (92.3%)
eu 406,608 366,478 (90.1%) 540,810 506,616 (93.7%)
kr 157,580 159,532 (101.2%) 241,545 248,954 (103.1%)
cn 190,302 91,791 (48.2%) 242,082 113,701 (47.0%)
sea 46,627 39,320 (84.3%) 64,293 55,633 (86.5%)
China had the same drop-off that all the other regions experienced going from season 1 to 2, because Starcraft 2 was released in China at the start of season 2. Everyone else stayed close to where they were before, even when season 3 was a month shorter than season 2!
Here are graphs of players over time. Brown is season 1, silver season 2, gold season 3. Season 1's data starts a month past release.
+ Show Spoiler [Graphs!] +
North America
Europe
Korea
China
Southeast Asia
Europe
Korea
China
Southeast Asia
Here are players with at least 25 wins (b.net doesn't track loses yayyy!) in 1v1, and all gametypes. Season 2 data has been time-modified (see bottom of post for details).
1V1 GAMES ALL GAMETYPES
S2 S3 % diff S2 S3 % diff
na 136,395 120,779 (88.6%) 237,884 259,278 (109.0%)
eu 140,974 123,365 (87.5%) 233,675 253,706 (108.6%)
kr 50,408 55,030 (109.2%) 77,404 109,113 (141.0%)
cn 77,843 35,735 (45.9%) 72,201 57,555 (79.7%)
sea 15,367 12,423 (80.8%) 25,390 26,087 (102.7%)
Graphs of similar data, between 0 wins (everybody) and 200 wins.
Brown is season 2, silver is season 3. Season 2 data is once again time-modified.
+ Show Spoiler [More Graphs!] +
North America
1v1
All
Europe
1v1
All
Korea
1v1
All
China
1v1
All
Southeast Asia
1v1
All
1v1
All
Europe
1v1
All
Korea
1v1
All
China
1v1
All
Southeast Asia
1v1
All
Attrition rate.
This consists of players that played in previous seasons, who returned in season 3. China didn't have a season 1, so its historical data is limited to season 2 only.
TOTAL PLAYERS RETURNED FROM % RETURNED IN SEASON 3 FROMEDIT: there were 210,505 new sc2 players in the last 3 months
s2 s3 all s2 all s2 s3 new players
na 655,751 551,524 476,235 430,924 41.67% 65.71% 13.65% 75,289
eu 588,015 506,616 435,159 397,139 44.66% 67.54% 14.10% 71,457
kr 270,220 248,954 199,158 172,744 29.78% 63.93% 20.00% 37,418
cn 260,235 113,701 76,283 76,283 29.31% 29.31% 32.91% 49,796
sea 70,238 55,633 49,088 44,691 36.57% 63.63% 11.76% 6,545
This one's moderately complicated, here's a short explanation.
In North America 65.71% of players that played in season 2, also played in season 3. 41.67% of players that played in seasons 1 or 2, also played in season 3. 13.65% of players in season 3 (of which there were 551,524) did not play in seasons 1 or 2.
edit: What is "time-modified" data?
Since season 2 lasted almost a month longer than season 3, the numbers for games played doesn't match up properly. I modify player numbers based on how many people I had logged at a time matching up to the length of season 3.
For example, Korea actually has 56,393 people with 25 or more wins, while my numbers in the table state 50,408. Season 3 lasted 90 days, while season 2 lasted 118 days. (118 - 90 = 28) At the end of season 2, Korea had 221,819 players. 28 days prior to the end of season 2, Korea had 198,281 players, which is 89.38864blahblahblah%. Multiply 56,393 (real number of >= 25) by this percent, and you get the value in the table of 50,408.
edit2: added labels to my graphs.
edit3: new players per region in attrition rate
tl;dr china plummets as expected first season, everyone loses a little total players, gains a little active players, korea beats the curve, worldwide quarter million new players