Plenty of sales managers run great contests on a spreadsheet, and pay for it with their weekend. The manual update is the tax, and it is the first thing to cut.
The hidden cost
Every manual update is time you are not coaching, plus the risk of a typo that makes a rep distrust the whole board. The busier you are, the later the board falls behind.
Automate the update
Upload your export and the standings re-score themselves. Better yet, connect your tool through the API so the numbers update without you touching anything.
Get your weekend back
When the board updates itself, contests stop being a chore and start being the thing that runs your floor while you focus on your reps.