Stumbled across this one when I was testing the efficiency of different decks.
Set my queue to switch to the next deck after x Games if the Winrate is below 60%.
After 30 games, the winrate for every deck was displayed as 0% in the queue, however the statistic show a variety of procentages up to 62%.
Seems there's an error in getting the correct amount of wins as number of played games works fine.
Greets