Calculating the seed/hold %

Hi there,

Was wondering how to calculate the seed/hold % of a mhb if you're aware of the rtp, the meter rate.

https://wizardofvegas.com/forum/gambling/slots/18030-must-hit-by-progressives-for-dummies/#post354826

You might check this older discussion.

(There is a really good writeup here, somewhere, but I can't find it just now. (Mission?))

Example 90% rtp
100$ moves meter 1$ on the minor

What other information is needed to figure out how much of the rtp is held in the progressive?

Quote: Westduck

Hi there,

Was wondering how to calculate the seed/hold % of a mhb if you're aware of the rtp, the meter rate.
link to original post

Let s = the seed, which is the starting amount of the progressive.
Let m = the must-hit-by amount.
Let r = the meter rate, which is the rise of the progressive divided by the coin-in.

I find that the meter's contribution to the slot's return-to-play (RTP) is: r.

And the seed's contribution to the slot's RTP is: 2 * r * s / (m - s).

[Or you can combine the meter's and seed's contributions to get: r * (m + s) / (m - s).]

When you say "rise of the progressive"

Do you mean the latest it can hit subtracted by the starting point?

Quote: Westduck

When you say "rise of the progressive"

Do you mean the latest it can hit subtracted by the starting point?
link to original post

No, but you can disregard that part of the sentence.

I should have typed:

Let s = the seed, which is the starting amount of the progressive.
Let m = the must-hit-by amount.
Let r = the meter rate.

(For those who don't know what "meter rate" is, it's the number of dollars the progressive went up divided by the number of dollars played. For example, if the progressive went up by $0.01 after I played $1.00, the meter rate would be $0.01 / $1.00 = 0.01 = 1%.)

Perfect.

One more thing.. how to account for the minor if you're playing solely for the minor

Quote: Westduck

Perfect.

One more thing.. how to account for the minor if you're playing solely for the minor
link to original post

For a machine with only two progressives, call the minor "1" and the major "2." The contributions of the seeds and the meters to the RTP would be:
r1 * (m1 + s1) / (m1 - s1) + r2 * (m2 + s2) / (m2 - s2)

Ignoring the minor and major, you would expect to lose this fraction (F) of money bet:
F = 1 - RTP + r1*(m1+s1)/(m1-s1) + r2*(m2+s2)/(m2-s2)

The minor would be expected to hit at (N1 + m1) / 2, where N1 means the size of the minor now.

The expected amount of money you would have to bet to hit the minor would be:
[(N1 + m1) / 2 - N1] / r1 = (m1 - N1) / (2 * r1)

Ignoring the major, set the expected amount of money lost along the way to what the minor would pay, and solve for the break-even value of the minor N1:
F * (m1 - N1) / (2 * r1) = (N1 + m1) / 2

Ignoring the major, the minor would have to be at least this amount to break even:
N1 = m1 * (F - r1) / (F + r1)

Thank you very much

r1 * (m1 + s1) / (m1 - s1) + r2 * (m2 + s2) / (m2 - s2)

After using this formula, I get a hold of .042

In your experience, could this be right for an ainsworth? Or is it too high and I mightve miscalculated?

Quote: Westduck

r1 * (m1 + s1) / (m1 - s1) + r2 * (m2 + s2) / (m2 - s2)

After using this formula, I get a hold of .042

In your experience, could this be right for an ainsworth? Or is it too high and I mightve miscalculated?
link to original post

Below are some data from the Wizard's page on Ainsworth must-hit-bys.

JACKPOT	MINOR	MAJOR
Starting point	$20	$350
Must hit by	$50	$400
Rate of increase (based on bet)	0.45%	0.20%

Using the above data, I get r1 * (m1 + s1) / (m1 - s1) + r2 * (m2 + s2) / (m2 - s2) = 0.0105 + 0.0300 = 0.0405 = 4.05%.

So, your 0.042 is comparable to the Wizard's example.

I don't check must-hit-bys, so I don't have any data of my own to compare.

Ty chesterdog