Ping pong electronic counter

We have a lot of struggling with counting the points at a pingpong game.
With this handy electronic counter there is no more arguing.
Also the person to serve is pointed with the leds.
I added 2 gamemodes to choose:
11 - the original table tennis rules (switch serve by 2 points)
21 - larger games (switch serve by 4 points)
The winner is who wins first 3 sets (best of five)

For this counter you need the led&key module.
This is a cheap arduino module with lots of possibilities.
You also need:
- arduino nano (or equivalent)
- battery contact springs
- 5V booster module (MT3608 step up power module)
- switch (19x6x13mm)
- 2x AA battery
- 4 small screws

Also added a mount for a mini tennis table.
The electronics are easy to assemble. Added fritzing scheme

Controlling keys:
Choose game mode 11 or 21 points to win (choose keys 1-4 or 5-8)
Choose which player starts to serve (blinking leds, choose keys 1-4 or 5-8)
key 1 and 8 - increment points (also increment serv