How to get a calculation or formula to insert its result in another cell?

eg say I want B1 = A1 + 2. The standard way is to put '=A1 + 2' in cell
B1. I want the formula to be elsewhere, not in B1.

Why do I need this?

My spreadsheet records the results in a big round-robin tournament.
There are many players each of whom play several opponents.

Possible scores are 5-0, 5-1 up to 5-4. Say Nick defeats David 5-3.
I want to be able to type just '3' in Nick-vs-David, and have 'Win 5-3'
appear there, and 'Loss 3-5' in David-vs-Nick (cell address known).
This ensures consistency and zero-sum ecven if the score is entered
erroneously.

Currently I am using drop-down lists, and the people entering the
results are making careless errors. There are complex follow-on
calculations which rely on the total being zero-sum, and errors cause
all subsequent calculations to fall over.