31. Games with pieces (white) on 6 and 15, (black) 36 and 45

White: M. Dolfing - Black: J. Wit (Nijmegen, The Netherlands 1993) 

White: B. Bies - Black: G. Boom (Championship of The Netherlands, 1998) 

32. Most played move (or ply) in the beginning of the game 

32-28.
Turbo Dambase 2002, which contains 255904 games, notices 139852 times 32-28.

33. Rarest move (or ply) in the beginning of the game 

32-27.
Turbo Dambase 2002, which contains 255904 games, notices 833 times 32-27.
Although 32-27 is not a bad move...

34. Most played move (or ply) for black after 1. 32-28

19-23.
The complete move 1. 32-28, 19-23; has been played 37618 times.
Second: the complet move 1. 32-28, 18-23; has been played 33559 times.

35. Rarest complete first move (white&black) 

1. 31-27, 16-21; and also 1. 32-27, 16-21; Not so surprising: black looses immediately a piece.
Then: 1. 32-27, 19-24;  this complete move has been played only 11 times. 

36. International draughts player who insisted in the same first move.

Maybe Piet van Heerde (The Netherlands). Nearly 99% of his 'white' games he started with 32-28.

37. Opening combination that made (and makes) the most victims.

The move of Lochtenberg.  
After 1. 31-27, 19-23; 2. 33-28, 17-21; 3. 28x19, 14x23; 4. 39-33, 10-14; 5. 33-28, 5-10; 6. 28x19, 14x23; 7. 44-39 is 10-14 a mistake; the moves 9-14, 11-17, 12-17, 13-19, 21-26, 20-24 and 20-25 are OK.

But 10-14 is in draughts history the second played move (21-26 is the most played). Totally 79 players played 10-14 and only 2 white players missed the combination.

38. Stongest player who was victim of the move of Lochtenberg

Nina Hoekman-Jankovskaja (once second in Ladies World Championship) in a game against Dieter van Gortel. But the player with black didn't won the game (draw).

39. Highest level with the elementary 'Haarlemmer' move on the second move. 

Challenge Mondial (=candidates tournament for the world championship) 1962. L. Reimann - A. Agliardi. Game: 1. 33-28, 18-22; 2. 39-33, 23-29. But Agliardi couldn't win with two pieces more.
But there are in draughts history some 'fakes':  1. 32-28, 18-23; 2. 37-32, 12-18; It can led to strange positions.

40. Strongest player who was victim of 1. 32-28, 18-23; 2. 33-29, 23x32; 3. 37x28, 16-21; 4. 39-33??, . . . 

Frans Hermelink in 1991 against Alex den Doop (both players from The Netherlands).