Master Gear Connector: 50 pins total or 25 on each side. I labeled them as 1A and 1B etc to show both sides.
Game Gear Connector: 45 pins total. The connector has pins on two rows. 22 pins on the upper row and 23 on the lower row
Game Gear Connector example:
2 4
1 3 5 etc
M: master gear pins
G: game gear pins
M G
1A. connect to 18A on Game Gear connector
2A. empty
3A. pin 34
4A. pin 32
5A. pin 30
6A. pin 27
7A. pin 24
8A. pin 22
9A. pin 20
10A. pin 16/18/41
11A. connected to pin 10A
12A. pin 14
13A. pin 12
14A. pin 10
15A. pin 8
16A. pin 6
17A. pin 4
18A. pin 2
19A. pin 36
20A. pin 38
21A. empty
22A. empty
23A. empty
24A. pin 40
25A. empty
1B. pin 3
2B. pin 26
3B. pin 33
4B. pin 31
5B. pin 29
6B. pin 25
7B. pin 23
8B. pin 21
9B. pin 19
10B. pin 17
11B. pin 15
12B. pin 13
13B. pin 11
14B. pin 9
15B. pin 7
16B. pin 5
17B. empty
18B. pin 28
19B. empty
20B. empty
21B. empty
22B. empty
23B. pin 3
24B. empty
25B. empty