I also dont thing the return of mana cristal is #turns-5, for the same reasons as DaFurryFury, but with opposite conclusion. I think on turn 6 if you have played mana cristal first turn you are still
way behind the player who did not casted it.
Let's consider 10 base channeling, and playing two mana crystal first turn (for maximizing example value)
No-Crystal-Player
turn 1: 20 mana and 2 actions - for whatever
[...]
turn 6: 70 mana - for whatever
Crystal-Player
Plating two mana crystals you have:
turn 1: 10 mana and no actions - for whatever
[...]
turn 6: 70 mana - for whatever
First of all, is not (number of turns - 5), but (number of turns - 6) since the turn casted does not provide channeling. On turn 6 you are on par mana wise (just two lacking quickcast later). You have no exponential value increase, since no-crystal-player may not use its 10 mana advantage and just keep it for getting high availability, if you value that. If you want to consider high mana availability as a bonus on turns 7+,
i think you have to take into account less mana availability during turns 1-5, during no-crystal-player has an advantage.
turn | Crystal | No-Crystal | diff |
1 | 10 | 20 | +10 |
2 | 22 | 30 | +8 |
3 | 34 | 40 | +6 |
4 | 46 | 50 | +4 |
5 | 58 | 60 | +2 |
6 | 70 | 70 | +0 |
7 | 82 | 80 | -2 |
8 | 94 | 90 | -4 |
9 | 106 | 100 | -6 |
10 | 118 | 110 | -8 |
11 | 130 | 120 | -10 |
12 | 142 | 130 | -12 |
I think the double mana crystal does not really breaks even until turn 11. Then the crystal-player have 10 more mana availble, but yat the cost of being on disadvantage during turns 1-6... which i consider have more impact than turns 7-11.
No-crystal player have 10 mana to cast a creature first turn. That creature have 6 turns to run onto the opponent and hit him (or even the crystals!) three times before the end of turn 6. It can be Timber wolf, Skeletal Sentry, or even a General Signet Ring plus Orc Butcher (you even got a discount ring then!). You have to take into account the 4-dice hitter actions during first turns. Sure, by turn 6 crystal player can cast it's own 4-dice creature, and by turn 10 a second one... But all in all i consider first turnhs more important and having more impact (you can disturb opponent's plan)