https://www.reddit.com/r/hearthstone...ewards/d8w72bl
Here's my short analysis:
number of wins - rewards (estimated value of rewards; 1 pack =100 gold, 1 dust = 1 gold, 1 golden legendary = 1600 dust = 1600 gold <- because this is how much you get when you disenchant one) - required win/lose ratio to reach this stage:
0 wins - 1 pack (100g) - 0%
1 wins - 2 packs (200g) - 25%
2 wins - 3 packs (300g) - 40%
3 wins - 4 packs+~120g+~120dust (~640g) - 50%
4 wins - 5 packs+~190g+~190dust (~880g) - ~57,1%
5 wins - 6 packs+~220g+~220dust (~1040g) - 62,5% <-- you need to reach this point to break even.
6 wins - 7 packs+~250g+~250dust (~1200g) - ~66,6%
7 wins - 8 packs+~280g+~280dust (~1360g) - 70%
8 wins - 9 packs+~310g+~310dust (~1520g) - ~72,7%
9 wins - 16 packs+~400g+~400dust (~2400g) - 75%
10 wins - 16 packs+~400g+~400dust+1 golden legendary (~4000g) - ~76,9%
11 wins - 16 packs+~480g+~480dust+2 golden legendaries (~5760g) - ~78,6%
12 wins - 50 packs+~1100g+~1100dust+3 golden legendaries (~12000g) - ~85,7% or more*
*NOTE: 85,7% = 12 wins / (12 wins + 2 loses) * 100%. The reason for this is that you can't go 12-3.