>>43262676All you need to know is to valuewhore as much as possible for card advantage
The more things the card does, for cheaper, the better.
Siege Rhino makes abzan #1 because it:
Gives you a fat body
Gives you life
Makes your opponent lose life
3 things in 1 card, it's pure value.
If 1 card only does 1 thing, it's probably shit. All the top decks just cram in as many cards in the right colors that give value.
Jace? Early game card draw, later transforms into a fucking planeswalker.
Like a 4:1 value, and it only costs 2 mana. An opponent spending mana to get rid of it is falling behind, especially if it hasn't been destroyed before it could churn out value.
Likewise for Siege Rhino, an opponent spending a card to get rid of it lost in card advantage because you've already drained them for 3.
If you're wondering why your deck is bad, it's probably because most of your cards have 1:1 value, while competitive decks stuff their decks full of cards that give 2:1 value or greater.