This thread originally started as a footnote to
this one, but became a veritable appendix. I decided to give it its own thread, as really it is a topic in its own right and I didn't want to clutter the other thread with math and unrelated conversation.
You are playing GAT. Your opponent is playing GAT. You are on the play. You fan open your 7 and see:
flooded strand, duress, gush, gush, misdirection, mystical tutor, mana drain
What do you do?
Personally I feel this hand has the potential to be quite strong assuming a land is found quickly. Though it does not contain brainstorm, it does contain turn 2 eot mystical -> turn 3 ancestral, and most enough disruption to back it up. First turn duress buys time and defends the hand's main vulnerabilities: opposing duress or too much early pressure... playing first makes making your second land drop turn 3 much more acceptable. Frankly, I think the hand is stronger than your average 6 card hand assuming you can play a second land turn 3 at the latest.
Here's some math, analysing the probability of topdecking a land or a cantrip that digs into land on your second turn, and the probability the mystical -> ancestral play succeeds if the first scenario does not occur. It is probably not perfect, I'm not up on my probability algebra, but it should be a reasonable guideline.
Situation A: drawing a land in your second turn draw step
10/53 = 0.188679245283018867924528301
88679% chance land drawn turn 2
0.188679245283018867924528301
88679% chance of Situation A
if this does not occur, my next favorable possibility is digging into a land. Since I will have U/B available if I draw a spell that could find a land, there are 3 spells which could possibly find me my second land drop on turn 2
Situation B: drawing a cantrip in your second turn draw step and finding a land with it
4/53 = 0.075471698113207547169811320
754717% chance brainstorm drawn turn 2
- 10/52 = 0.192307692307692307692307692
30769% chance land drawn card 1
-- 10/51 = 0.192307692307692307692307692
30769% chance land drawn card 2
--- 10/50 = 0.2% chance land drawn card 3
these are all favorable outcomes... the chances of drawing a second land don't matter because that only happens if you've drawn the first and the brainstorm is already favorable. So I believe the math here is additive...
= 0.584615384615384615384615384
614% chance brainstorm nets land
chance of drawing brainstorm * chance brainstorm nets land =
0.044121915820029027576197387
517619% chance of brainstorm -> land
3/53 = 0.056603773584905660377358490
566038% chance opt drawn turn 2
- 10/52 = 0.192307692307692307692307692
30769% chance land drawn card 1
-- 10/51 = 0.196078431372549019607843137
2549% chance land land card 2
= 0.384615384615384615384615384
614% chance opt nets land
chance of drawing opt * chance opt nets land =
0.021770682148040638606676342
525306% chance of opt -> land
1/53 0.018867924528301886792452830
188679 chance ancestral drawn turn 2
- 10/52 = 0.192307692307692307692307692
30769% chance land drawn card 1
-- 10/51 = 0.192307692307692307692307692
30769% chance land drawn card 2
--- 10/50 = 0.2% chance land drawn card 3= 0.584615384615384615384615384
614 land from ancestral
= 0.584615384615384615384615384
614% chance ancestral nets land
chance of drawing ancestral * chance ancestral nets land =
0.011030478955007256894049346
87911% chance of ancestral -> land
again, the chances of drawing each of the spells is mutually exclusive, so again unless I am mistaken the math is additive again:
chance of brainstorm -> land + chance of opt -> land + chance of ancestral -> land =
0.076923076923076923076923076
921112% chance of spell -> land
0.076923076923076923076923076
921112% chance of Situation B
now, if none of this occurs, my third turn draw phase will net me ancestral recall via mystical tutor and I will see 3 cards after having drawn 2.
Situation C: tutoring for ancestral, casting it turn 3 and finding a land with it
10/51 = 0.2% chance of drawing land card 1
10/50 = 0.204081632653061224489795918
36735% chance of drawing land card 2
10/49 = 0.208333333333333333333333333
33333% chance of drawing land card 3
= 0.612414965986394557823129251
70068% chance ancestral nets land
So now, situation A and B are mutually exclusive so I believe they are additive. That means about a 26.5% chance of making my turn 2 land drop. If that fails (73.5%), I have a 61% chance of that fraction leading to a land drop on turn 3, which settles out at about 45% of all possible scenarios. These two probabilities are mutually exclusive so an overall 28.5% chance the hand doesn't find land before the fourth turn and consequently be awful (71.5% chance of success).
I'm going to go ahead and assume that not finding land turn 3 probably leads to a game loss, even though the game I played with this hand didn't pan out that way. I'm also going to assume the duress + misdirection is enough to defend your land-finding attempts. These two ignored possibilities probably cancel each other out, or pretty close.
Feel free to correct my math but I'd still put 71.5% chance of playability as comparable to the average 6 card mulligan hand... I elected not to mulligan as I felt my chances of the new hand being playable were comparable.
What's
your call?