Probably d5 because of the Queen's Gambit.
Red Squares

I feel like we shoudl get a programmer to input a database of games and display the red squares by pictograph.

I feel like we shoudl get a programmer to input a database of games and display the red squares by pictograph.
Interesting. I'll try to do that as soon as I get the time. Hopefully tomorrow or some such.

Ok, based on ~1.2 million games (Fritz 10 database, mainlines only): (very crude plot, sorry)

Total number of positions: 88427598
White: 418303 (37.0902413375445%), Draw: 384718 (34.1123144392879%), Black: 324777 (28.7974442231676%)
Captures on squares:
d4: 1460792
d5: 1373153
e5: 982899
e4: 870635
f6: 635198
c4: 616804
c5: 603078
c3: 572250
c6: 515947
f5: 507601
f4: 442302
f3: 434606
b5: 427202
e6: 398345
d6: 388385
b4: 360162
g5: 349106
g4: 313109
d3: 292298
e3: 281322
g6: 278833
e7: 253181
d7: 241113
b3: 235187
b6: 220220
g3: 210756
d2: 209934
d8: 208504
g7: 206786
f7: 184185
d1: 175538
e2: 175149
a4: 174744
b7: 173767
b2: 170886
a5: 158705
g2: 158217
h5: 154529
a6: 153211
f2: 138975
c8: 136916
h4: 135380
h6: 134904
c2: 119706
c7: 117911
e8: 116406
c1: 115934
f8: 114494
a3: 110619
e1: 104014
a2: 102846
a7: 101314
f1: 99840
h3: 98287
h7: 86163
a8: 72056
h2: 61263
a1: 57699
b8: 48670
b1: 42238
h8: 25852
g8: 24378
h1: 21248
g1: 20051
Square by Square Statistics:
72056486701369162085041164061144942437825852
10131417376711791124111325318118418520678686163
153211220220515947388385398345635198278833134904
1587054272026030781373153982899507601349106154529
1747443601626168041460792870635442302313109135380
11061923518757225029229828132243460621075698287
10284617088611970620993417514913897515821761263
5769942238115934175538104014998402005121248

Something went wrong with the tab character in the last section. With commas instead:
Square by Square Statistics:
72056,48670,136916,208504,116406,114494,24378,25852
101314,173767,117911,241113,253181,184185,206786,86163
153211,220220,515947,388385,398345,635198,278833,134904
158705,427202,603078,1373153,982899,507601,349106,154529
174744,360162,616804,1460792,870635,442302,313109,135380
110619,235187,572250,292298,281322,434606,210756,98287
102846,170886,119706,209934,175149,138975,158217,61263
57699,42238,115934,175538,104014,99840,20051,21248
In this thread, when I say "red squares", I'm referring to a square on the chess board on which a chess piece gets captured.
So I thought of an interesting inquiry: what is the most common red square? Or in other words, on which square have pieces died the most often?
What do you think?