With regards to people saying Wheel of Potential et al "don't work as written", they should take a look at rule 107.3f. Specifically: "Sometimes X appears in the text of a spell or ability but not in a mana cost, alternative cost, additional cost, or activation cost. If the value of X isn’t defined, the controller of the spell or ability chooses the value of X at the appropriate time (either as it’s put on the stack or as it resolves)."

FYI

Re: how should wheel of potential workThe way wheel of potential *TECHNICALLY* works right now is a 3 mana sorcery that says exile your hand and draw any number of cards. The way it’s currently worded works like this: 1. I cast wheel of potential2. I begin to resolve wheel of potential. First I get three energy3. Next declare a value for X. This is where the card starts to break.4. Once I declare a value for X, two things happen based on that value, completely independent of eachother.4a. I am given permission to pay X energy4b. Each player is given permission to exile their hand and draw X cards.
The issue here is that step 4b is tied to step 3, not 4a. It’s obvious that the intended design for this card is for the amount you draw to be determined by the amount of energy you pay. But with its current wording, you can declare X to be any number you want, and you get to draw X cards regardless of whether you pay any energy. I think you see the problem.

To quote Matt Tabak on Twitter:“No, if you don’t pay the energy, you don’t draw the cards. We may have to tweak that template, but the card doesn’t work that way.” #WotCstaff