The Brainstorm Coefficient

[bruizar]

I would hereby like to suggest the concept of the brainstorm coefficient.

A lot of times, the dominance of blue and the health of the metagame are tracked using figures of the use of brainstorms in top 8s. I believe this method is seriously flawed as i overlooks how many brainstorms were competing for a top 8 place. If there are 1000 brainstorms in a tournament of size 250, then the brainstorm brainstorm coefficient is 1, signalling equal chances to all players. If the brainstorm coefficient is higher then 1, the use of brainstorm is favored to winning the tournament (the higher the coefficient the more you require brainstorm for a top 8. If the brainstorm coefficient is lower than 1, Brainstorm is a subpar choice in that particular tournament.

Here is the simple formula:
Average brainstorms per deck in top 8 / average brainstorms per deck in total tournament

Will edit this post tomorrow, but feel free to discuss. (Posted from iphone. There are limitations,as eith any model, which i wiil emphasize later on)

[Barook]

Hasn't this topic been discussed to death?

As long as we don't have said data that shows the number of Brainstorms at the start of the tournaments, we're going to go round in circles.

The closest thing we have to that is the Day 2 list of GP Paris (http://archive.wizards.com/magic/magazine/article.aspx?x=mtg/daily/eventcoverage/gppar14/standdeck).

Feel free to run those numbers as example. IIRC, The higher you go in terms of placing, the higher the Brainstorm deck percentage gets.

[DLifshitz]

I would hereby like to suggest the concept of the brainstorm coefficient.

Here is the simple formula:
Average brainstorms per deck in top 8 / average brainstorms per deck in total tournament


That would make it the Brainstorm ratio, rather than the coefficient. A coefficient is something you multiply by.

And it would not actually be a very good statistic measure of the dominance of blue. If everybody always played 4 Brainstorm, this ratio would always be equal to 1, when in fact blue would be completely dominant. I imagine that in reality, on average some 50-70% of players use 4 Brainstorm, so this ratio can never be very high.

[Lord Seth]

Hasn't this topic been discussed to death?

As long as we don't have said data that shows the number of Brainstorms at the start of the tournaments, we're going to go round in circles.

The closest thing we have to that is the Day 2 list of GP Paris (http://archive.wizards.com/magic/magazine/article.aspx?x=mtg/daily/eventcoverage/gppar14/standdeck).

Feel free to run those numbers as example. IIRC, The higher you go in terms of placing, the higher the Brainstorm deck percentage gets.Actually, the Bazaar of Moxen was nice enough to give a full metagame report for their Legacy event, which can be seen here (http://www.bazaar-of-moxen.com/en/bazaar-of-moxen-coverage-bom9,24/bom9-legacy-main-event,c147.html) (the metagame breakdown is near the bottom). It doesn't say the number of Brainstorms in the decks, but it should be pretty obvious by what the decks are (e.g. Death & Taxes doesn't have Brainstorm, BUG Midrange is basically guaranteed to have 4). Admittedy, it's just one data point, but it's the only big Legacy tournament I can think of where the metagame information of the entire field is provided.

[TheArchitect]

Actually, the Bazaar of Moxen was nice enough to give a full metagame report for their Legacy event, which can be seen here (http://www.bazaar-of-moxen.com/en/bazaar-of-moxen-coverage-bom9,24/bom9-legacy-main-event,c147.html) (the metagame breakdown is near the bottom). It doesn't say the number of Brainstorms in the decks, but it should be pretty obvious by what the decks are (e.g. Death & Taxes doesn't have Brainstorm, BUG Midrange is basically guaranteed to have 4). Admittedy, it's just one data point, but it's the only big Legacy tournament I can think of where the metagame information of the entire field is provided.

Its older data at this point, but BoM is the biggest sample to report these kind of statistics in 2014. BTW, this comes to 55-66% Brainstorm prevalence with the discrepancy being due to 11% of the decks falling into the "Other" category. This about the same prevalence we've had for as long as I can remember.

For reference there was a 52.2% brainstorm prevalence at BoM 4 back in 2010, things have not changed that much: http://www.mtgthesource.com/forums/showthread.php?17849-Article-Metagame-Breakdown-and-Analysis-Bazaar-of-Moxen-4-Legacy-Main-Event


Hasn't this topic been discussed to death?

As long as we don't have said data that shows the number of Brainstorms at the start of the tournaments, we're going to go round in circles.

The closest thing we have to that is the Day 2 list of GP Paris (http://archive.wizards.com/magic/magazine/article.aspx?x=mtg/daily/eventcoverage/gppar14/standdeck).

Feel free to run those numbers as example. IIRC, The higher you go in terms of placing, the higher the Brainstorm deck percentage gets.

Counting up the brainstorm decks from we get 65% (120 of 185).

[nedleeds]

The only Brainstorm that mattered at GP Paris was the one used to cheat on camera at the end :laugh:

[bruizar]

Will edit later