I posted this last October about some of the charters CO run:

http://flyertalk.com/forum/showpost....7&postcount=22

Right now:

Indians - mostly 738, occasionally a 752 or 733.
http://flightaware.com/live/flight/COA1901

Orioles - also 738, occasionally a 737 or 733.
http://flightaware.com/live/flight/COA1907

Yankees was 1908 till end of June. 738 or 752.
http://flightaware.com/live/flight/COA1908

This one looks like the Texans. 753 to PHX last weekend:
http://flightaware.com/live/flight/COA1917

The Bucs, a 753 just like last year:
http://flightaware.com/live/flight/COA1919

1930-33 seem to be deadhead flights to serve the charters.

Not all 19xx flights are charter. For example, 1941-45 were used the last week for extra flights to CUN/CZM/MID etc to evacuate people.

Sometimes you can book on a 19xx flight. Like the upcoming 9/7 SEA-EWR 1991 and 9/9 EWR-SEA 1990 on the 772:

http://flyertalk.com/forum/showthread.php?t=720894