(Open the image in a new tab to look at it in a readable size)
The statistics and what they mean are to go as follows.
- Mulligan WR: Average win rate of games when the card ends up in the opening hand.
- Kept: Percentage of the times the card was kept when presented in the mulligan.
- Drawn WR: Average win rate of games where the card was drawn at any point or ended up in the opening hand.
- Played WR: Average win rate of games where the card was played at any point
- Turns Held: Average number of turns the card was held in hand.
- Turn Played: Average turn the card was played on.
Also worth mentioning the sample size of the data displayed in the picture is out of 5,100 games during the last thirty days and it was last update 20 minutes ago at the current writing of this at 9:18AM Mountain Standard Time. So the data is up to date it also is collecting data from Legend all the way down to Rank 25.
Above is a Mulligan Guide, A.K.A the cards that are best to have in hand at the start of the game, And which cards to get rid of. For example: If you are going first and draw three cards and start with coin and you have a "Savannah Highmane" an "Alley Cat" and a "Kill Command" based off of the percentages above with the highmane having a win percentage of 49.0% When drawn in the starting hand and most people keeping that card 4.1% of the time you are definitely going to mulligan it. The same goes for "Kill Command" with it having a win rate of 49.3% and a keep rate of 24.1% You are going to mulligan that as well. "Alley Cat" however has a win percentage of 62.6% and a keep rate of 98.3% you are always going to keep the alleycat because of it's turn one capability.
Obviously, some scenarios may call for different mulligans but this is a good guide to follow until you have an understanding of what you're going to be going up against and how you should react to certain classes (i.e what to mulligan and why)
A deck that Toast used to climb to legend.
https://youtu.be/o2TlqswALdg (Link to the video in which he showcases the deck)
Edit: Some substitutions you can try out as well that he didn't include in his original make due to it trying to be as F2P as possible are the "Kindly Grandmother" and the "Rat Pack" which you substitute for the "Fire Fly" and the "Ravasaur Runt". Another substitution you can make is if you are lacking one Savannah Highmane you could include a "Faceless Manipulator" as "S3NS0R" suggested in the comments. I agree that this would be a good substitution because it has synergy with many of the other cards one of those obviously being savannah highmane but it can also have use with cards such as "Scavenging Hyena" to make a 3/3 version that gains +2/+1 off of friendly beasts dying, If you already have a hyena on the field it could be used to make another copy of "Infested Wolf" which then allows you to hopefully buff your hyena even more since if both wolves die it gets +4/+2 and you get four more beasts that are 1/1 that could equivalete to another +8/+4 on the "Scavenging Hyena" this particular scenario would work most effectively if you have a "Tundra Rhino" to allow your beasts to have charge allowing immediate trade-ins with your 1/1's received from "infested Wolves" or if you have "Savannah Highmane" immediate trade-ins with your 2/2 Hyenas.
That is one thing I have learned with this deck and something you need to try to do is to play around your "Scavenging Hyena" because of the buff it gets and the fact that you have many low balling beasts you are trying to ensure that it gets its buffs, all the cards in this deck in some way or another synergize with your hyena.
You can obtain the "Kindly Grandmother" from the adventure "One night in Karazhan" during the "Opera" Wing and the "Rat Pack" card can be obtained in "Mean Streets of Gadgetzan" packs or crafting two of them costs 800 dust