Basically an individual stock has to increase by 25% if it s a...

Basically an individual stock has to increase by 25% if it s a Long tip or decrease by 25% if its a Short tip. Think of Short like Short sellers, they are tips that the share price is going to go down.
The accuracy in the first list is over multiple tips. Therefore if you have made 10 tips but get 5 wins, then your accuracy would be 50%.
To be honest you seem very critical of the comp, but it's actually harder than you think to get a good accuracy, especially in the timeframe of 28 days.