Ex. Suppose I re-spin the first four reels so that the "blueberry" symbol appears on each of them. If I respin the 5th reel, the blueberry symbol shows up less than 5% of the time??? I did one experiment where out of 97 spins of one the reels, the blueberry symbol only showed up 3 times! On the other hand, if I don't have a blueberry on each of the four other reels, then a blueberry will show up about 50% of the time if I respin the 5th reel!
Also, I definitely should've mentioned this earlier but the trial where I got 3/97 successes also had the "HORSESHOE" and "STAR" symbol on three and four of the reels as well. I was re-spinning the 2nd reel in this case (as reels 1,3,4 and 5 all had the pool ball blueberry symbol).
You are comparing apples to oranges here: respinning reel#2 vs spinning reel#5. Here are the layouts for these two reels:
Reel#2: 0,7,9,5,7,2,9,5,6,9,1,7,3,9,4,7,9,3,7,9,4,7,12,9,4,7,9,5,7,4,9,7,3,9,8,7,10,3,7,9,5,11,7,9
Reel#5: 0,6,7,8,3,10,6,5,7,4,8,6,10,5,8,3,9,1,6,5,8,9,4,6,3,8,9,2,10,11,7,8,3,9,10,12,7,2,10,9,7,10,9,7
(10 = Blueberry, 0 = Wild, 8 = Shine Star)
So there's only 1 blueberry on reel 2 out of the total of 44 symbols. We have 4 horizontal lines, so the probability of seeing a blueberry on a random spin of reel #2 equals 4/44 = 0.09
Now, assuming independent spins, the probability of seeing 3 or less blueberries out of 97 spins equals 0.02 - which is pretty small, but way short of being a sign of a problem.
On reel 5 we have 6 blueberry symbols, and two of them are close enough to appear on one screen, so exact probabilities will be a little tricky, but a rough (6*4)/44 = 0.54 is pretty close to your estimate of 50%.
And now, here is how the cost of a respin is calculated. Assume the slot positions are:
Old Attachment (Invalid)
The 10 possible winning combinations for reel# 2 respin are
0,7,9,5 Payout = 275
7,3,9,8 Payout = 25
3,9,8,7 Payout = 25
9,8,7,10 Payout = 275
8,7,10,3 Payout = 275
7,10,3,7 Payout = 250
10,3,7,9 Payout = 250
11,7,9,0 Payout = 275
7,9,0,7 Payout = 275
9,0,7,9 Payout = 275
The remaining 34 produce a 0 payout, so assuming all 44 have an equal probability the average payout is the simple summation of the above numbers divided by forty four, 2200/ 44 = 50 cents even. Finally, to account for the 2.5% HA we need to divide it by 0.975, and we get 51.28. And then Microgaming rounds it up to 52 cents.
BTW, this rounding is their trick, the actual HA effectively becomes higher than 2.5% if your bet is small (in my example it equals 3.8%), and WAY higher than 2.5% if you bet the bare minimum (can be as high as 10% in some cases, an RTP of 90% !)
It's definately alarming. This indicates that the game clearly remembers your choice and the outcome is not random.
