Depends on which chest are you opening. there are a lot of different chests
Don't buy chests...There is multiplied chance to get the worst loot :). So you propably always get the worst loot from it and there is always 1 in these chests....Use soul gems for buying games directly or gaming currency or prepaid cards to buy these games cheaper in discounts on these pages (Kinguin, Steam wallet etc.) 
just buy the games or the curency... jdont go for chests there is a 99.99 chance to get the worst loot in it
Yeah, you will most likely get the worst loot. Only open the christmas chests that are in your inventory as they are worth it, and become free at a certain amount of siul gems that you pass!
in 3 steps
Choose the game that interests you and play itfor free.
Every game has some quests for which you will receive Soul Gems.
You can exchange your Soul Gems for Steam Wallet top-ups, game keys, CS:GO Skins and other rewards.
You know that on Gamehag you can get real rewards for free, right? Join us, complete walkthrough and get your chest!
How much chance to get a game from a chests ??