Appendices
Slots Analysis
Miscellaneous

3 reel slots were invented in San Francisco in 1887. These original machines were known as One Armed Bandits and were the inspiration for modern 3 reel slots that you can find in many online casinos. Click here to see a list of 3 reel slots. 3 reel games are defined by the fact that they have three spinning 'reels' with pictures. Slots don’t get further back to basics than Sizzling 7s. The three reels house big and bold symbols, a throwback to the early days of Las Vegas slots. The $1 minimum coin stake make for a simple process of calculating any winning combinations, and the choice of stake up to a maximum of $3 isn’t unreasonable as you will often get a fair game.

Blazing 7s Slots Community. The BEST 3 reel slots to play – straight from Downtown Vegas casinos and the Strip Viva Las Vegas!

Introduction

In my continued efforts to show the world how video slot machines work, I set out to deconstruct how Blazing Sevens was designed by playing it. There are lots of different 'Blazing Sevens' games. The one I am referring to is the five-reel video slot. Armed with a cell phone camera, I recorded about 30 minutes of play. Unlike most video slots, Blazing Sevens has no bonus round. To analyze the game, all I needed to do was piece together the reel strips based on my videos and then do the math.

Step One - Data Collection

Much like games I previously deconstructed, Jackpot Party and Hexbreaker, I chose Blazing Sevens because it didn't involve bonus spins. The only mystery was the reel stripping. So I found a game in the Fremont in downtown Las Vegas and recorded 30 minutes of play. These videos can be found on YouTube:

Blazing Sevens part 1(10:07)
Blazing Sevens part 2(9:12)
Blazing Sevens part 3(10:04)

When I returned home, I asked for volunteers to record each sequence of three symbols on all five reels for every spin. I would like to thank Miplet for transcribing part 1 and ChesterDog for part 3. Those two videos I felt were sufficient.

Step Two - The Reel Strips

Then I tried to put together the order of the reel strips, based on the observed sequences of symbols. To make the reels balance and loop around, I assumed that some sequences appeared more than once on the same reel strip. These were chosen according to what completed the reels and which sequences occurred more frequently. The reel strips below I believe are very close approximations to the actual ones. However, due to repeating sequences, and a limited sample size of 617 spins, they are probably not exactly correct. I estimate that each reel may have about two incorrect symbols in terms of frequency.

The following table shows how often each three-symbol sequence appeared on each reel in videos 1 and 3. For example, the D-7-1 (dollar, plain seven, 1-bar) sequence appeared 14 times on reel 1.

Blazing Sevens Sequence CountsExpand

Reel 1		Reel 2		Reel 3		Reel 4		Reel 5
Sequence	Count	Sequence	Count	Sequence	Count	Sequence	Count	Sequence	Count
2B1	41	B2D	40	27D	38	1BD	30	F2D	34
B27	37	2D3	33	B27	35	F1B	30	BF2	29
3B2	29	1B2	28	7DB	32	17D	25	DBF	27
B1D	28	FDB	21	D3B	26	3F1	25	2F1	25
372	27	7DF	20	F2B	22	1D7	22	BD2	22
72B	27	DBF	20	1B7	21	7B3	21	2DB	21
73B	24	BF7	19	DBF	21	B2D	21	7B2	21
3D7	23	D71	19	FD3	21	BF3	20	7BF	20
7DB	21	7D2	18	1D3	19	D72	20	FBD	20
D37	21	B17	18	B2D	19	2BF	19	F1D	19
1B7	20	BF3	18	D1B	19	71B	19	F37	19
1D7	20	DFB	18	B7F	18	72B	19	DB1	18
B73	20	F7D	18	DF2	18	7D2	19	73B	17
F2B	19	371	17	3FB	17	3DF	18	F73	17
BD3	18	7D1	17	DB1	17	F17	18	173	16
27D	17	D2B	17	DB3	17	F3D	18	1DB	16
71B	17	D3B	17	1DB	16	B3D	17	3FB	16
D3B	17	3DB	16	3B1	16	D27	16	3FD	16
B37	15	D1B	16	B1D	16	F3B	16	7F2	16
B3D	15	F2B	16	D27	16	B3F	15	BF7	16
DB3	15	FB7	16	DB2	16	27B	14	F7B	16
1B2	14	2D1	15	FB2	16	2B3	14	2F3	15
B2D	14	B7D	15	2BF	15	2D1	14	B1F	15
D71	14	D1F	15	2DB	15	D1F	14	B7F	15
D73	14	17D	14	3B2	15	3B1	13	BF1	15
2D1	13	2B1	14	F1D	14	73F	13	D2F	15
3F2	13	BD7	14	7DF	13	D17	13	2B7	14
1D3	12	2BF	13	B17	13	DF1	13	F17	14
3BD	12	71B	13	BFD	13	1F3	12	FDB	14
D1B	12	F3D	13	FD2	13	B1D	12	1F7	12
2B3	11	1FD	12	7D1	12	BD1	12	B2F	12
273	9	3BD	12	BF1	12	D71	12	F2B	12
73F	8	71F	12	B3F	10	173	11	2D3	11
1F2	11	17D	8	3D7	11	73F	10
D37	11	7FD	8	BD2	11	D3F	9
DB2	11	1B2	10	3BF	7
D2B	10	37B	6
Total	617	Total	617	Total	617	Total	617	Total	617

My sidekick, JB, then wrote a program to assemble the combinations in order. It should be noted that given the sequences observed, multiple solutions are possible. The reel strips below are just one possibility. However, all of them would have the same expected return.

Blazing Sevens Reel Strips

Position	Reel 1	Reel 2	Reel 3	Reel 4	Reel 5
1	2	D	7	7	2
2	D	F	D	D	F
3	1	B	B

3 7's On A Slot Machine