# Computing max games for knockout tournament?

I am organizing a 3 strikes knockout tournament (using brackelope) and getting ready to submit to ifpa website. Does anyone know an easy formula for computing the max games for a given number of players?

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perfect! thanks!

Correct me if Iâ€™m wrong, @iscrz, but my understanding is that when you email the results from Brackelope, the email has a .txt attachment that includes the TGP in the form of â€śmeaningful matches playedâ€ť so you donâ€™t even need to figure it out. Hereâ€™s an example from the most recent Portland tournament:

Adjusted Results for the World Pinball Player Rankings
Name: Clinton Street 5/26
Date: 2015-05-26
Format: Double Elim. Bracket
Meaningful Matches Played: 12
(Multiply by games per match. See http://www.ifpapinball.com/menu/tgpguide)

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CFFLegsâ€“this issue is estimating max games BEFORE the tournament happens, when you are submitting to the calendar

Ah, gotcha. Since it doesnâ€™t affect the point totals in the end, I just always go with the same number of estimated players so I know the corresponding TGP for whatever format to enter for all calendar submissions (I always guess 30 players will show up, which means 11 TGP for single game/double elimination and 17 TGP for single game/three-strike knockout, the two most common formats for our weekly tournaments in Portland). That way I donâ€™t have to think too hard

floor(log2(players - 1.0)) x strikes + (2 x strikes) - 1

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nerrrrrrrrrrrrrrrrrrrrrrd. (did i add enough "r"s for it to approve my post?)

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nice! what is the floor parameter? or is there an â€ś=â€ť missing?

Edit: yep, just ignore the â€śfloorâ€ť part. checked the formula against pinwizjâ€™s sheetâ€“cool!

floor(x) is the largest integer thatâ€™s not larger than x.

mmmm, never used that function before.

floor(x) and ceil(x) are common programing functions that round decimals down and up, respectively

There usually a round(x) function too but Iâ€™ve never seen a round() function I could trust.

Mathematicians canâ€™t even agree on what rounding should do in some special cases, so itâ€™s not surprising that one working on floats has some dodgy interactions, especially with decimal numbers.

Floor and ceil arenâ€™t just for programming: they come up in more abstract maths fairly often, like @bkerinsâ€™s formula above or in various infinite limits.

Does 4.49999999â€¦ round to 5?

Depends what youâ€™re doing with it

(For data analysis, itâ€™s often correct to round terminal 5s to the nearest even digit to avoid bias.)