These are worked out after each competitive race - the nearer a skier finishes to the winner, the more points are deducted from their score.
Nkrumah-Acheampong started out with a rating of 1,000 and has steadily brought his tally down.
He finally made it below the magical 140 point barrier after skiing in the Italian Alps this winter.
His place in next year's Winter Olympics is now guaranteed.
"It has taken me about four years, because I missed the [2006 Winter Olympics in Turin]... so its been a tough journey but I'm glad all the hard work has paid off."
Nkrumah-Acheampong has had a lot of support throughout his relatively short career from his family and from his community back home.
But he admits he did come up against some scepticism from people when he first announced his ambition.
The idea of a black man from Africa on the ski slopes was too much of a novelty for some.
But he has remained focused on his goal throughout.
"Some people where sceptical, others just did not believe that it was possible to train in such a short period of time and try and qualify, but I think now I can stand up and say it's possible," he says.
Now that scepticism has turned to pride as he becomes the first Ghanaian to qualify for the Winter Olympics.
"I think now people are going to sit up and say, OK, well he's done it this time, he's qualified and definitely we are going to see the Ghanaian flag in Vancouver."
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