Meb running yet another 2:09 got me curious as to how many Americans have run under 2:10 and how many of them were done in the "wind years" in Boston. I believe there were strong aiding winds in 1975, 1983, 1994, and 2011. I think 1979 may also have been one as well. So 7 out of 36 performances were aided by wind at Boston, 9 if you count 2010.
My source was
http://www.alltime-athletics.com/mmaraok.htm
The top 10 is entirely Ryan Hall and Khalid Khannouchi.
1. Ryan Hall - 2:04:58 Boston 2011 (wind year)
2. Khalid Khannouchi - 2:05:38 London 2002
3. Khalid Khannouchi - 2:05:56 Chicago 2002
4. Ryan Hall - 2:06:17 London 2008
5. Khalid Khannouchi - 2:07:01 Chicago 2000
6. Khalid Khannouchi - 2:07:06 London 2006
7. Ryan Hall - 2:08:04 Chicago 2011
8. Ryan Hall - 2:08:24 London 2007
9. Ryan Hall - 2:08:41 Boston 2010
10. Khalid Khannouchi - 2:08:44 Chicago 2004
11. Bob Kempainen - 2:08:47 Boston 1994 (wind year)
12. Alberto Salazar - 2:08:51 Boston 1982
13. Dick Beardsley - 2:08:53 Boston 1982
14. Abdi Abdirahman - 2:08:56 Chicago 2006
15. Greg Meyer - 2:09:00 Boston 1983 (wind year)
16. Ryan Hall - 2:09:02 Olympic Trials 2007
17. Meb Keflezighi - 2:09:13 New York 2011
18. Meb Keflezighi - 2:09:15 New York 2009
19. Alberto Salazar - 2:09:21 Fukuoka 1983
20. Meb Keflezighi - 2:09:21 London 2009
21. Meb Keflezighi - 2:09:26 Boston 2010
22. Bill Rodgers - 2:09:27 Boston 1979 (wind year I think)
23. Alberto Salazar - 2:09:29 New York 1982
24. Ron Tabb - 2:09:31 Boston 1983 (wind year)
25. David Morris - 2:09:32 Chicago 1999
26. Jerry Lawson - 2:09:35 Chicago 1997
27. Dick Beardsley - 2:09:37 Grandma's 1981
28. Ken Martin - 2:09:38 New York 1989
29. Ryan Hall - 2:09:40 Boston 2009
30. Alberto Salazar - 2:09:40 New York 1980
31. Alan Culpepper - 2:09:41 Chicago 2002
32. Meb Keflezighi - 2:09:53 New York 2004
33. Bill Rodgers - 2:09:55 Boston 1975 (wind year)
34. Meb Keflezighi - 2:09:56 New York 2005
35. Meb Keflezighi - 2:09:56 Boston 2006
36. Benji Durden - 2:09:57 Boston 1983 (wind year)
Ryan Hall - 7
Meb Keflezighi - 7 (all in the 2:09's, he also ran a 2:10:03)
Khalid Khannouchi - 5
Alberto Salazar - 4 (5 if you count the 2:08:13 in NYC in 1981, which had to have been worth a sub 2:10)
Dick Beardsley - 2
Bill Rodgers - 2
And in the close category, there were 18 more performances between 2:10:00 and 2:10:29, led by Ritz's 2:10:00. Bill Rodgers, Jerry Lawson, Jeff Wells, and Tony Sandoval all had 2 of the 2:10:00 - 2:10:29 performances.