JenniferMurphy
Well-known Member
- Joined
- Jul 23, 2011
- Messages
- 2,687
- Office Version
- 365
- Platform
- Windows
This is really a statistics question. If this is inappropriate, let me know. I've tried getting help in a couple of statistics forums, but I always get better answers here and I know Excel is often used for statistical calculations.
I am interested in comparing the "tally errors" is different "win streaks" in a random event, like a game, with a given probability of a win. The table shows results for win streaks of various lengths (Row 5). Columns D-G contain data for these 4 streak lengths over 4,000 games with an overall winning % (Wins/Games) of 60%.
Col H shows the formulas used for the calculations.
[TABLE="class: grid, width: 650"]
<tbody>[TR]
[TD="align: center"]R/C[/TD]
[TD="align: center"]C[/TD]
[TD="align: center"]D[/TD]
[TD="align: center"]E[/TD]
[TD="align: center"]F[/TD]
[TD="align: center"]G[/TD]
[TD="align: center"]H[/TD]
[/TR]
[TR]
[TD="align: center"]3[/TD]
[TD]#Games[/TD]
[TD="align: center"]4000[/TD]
[TD="align: center"]4000[/TD]
[TD="align: center"]4000[/TD]
[TD="align: center"]4000[/TD]
[TD]D3: 4000[/TD]
[/TR]
[TR]
[TD="align: center"]4[/TD]
[TD]Win %[/TD]
[TD="align: center"]60.00%[/TD]
[TD="align: center"]60.00%[/TD]
[TD="align: center"]60.00%[/TD]
[TD="align: center"]60.00%[/TD]
[TD]D4: 0.6[/TD]
[/TR]
[TR]
[TD="align: center"]5[/TD]
[TD]Streak Length[/TD]
[TD="align: center"]1[/TD]
[TD="align: center"]2[/TD]
[TD="align: center"]3[/TD]
[TD="align: center"]4[/TD]
[TD]D5: 1[/TD]
[/TR]
[TR]
[TD="align: center"]6[/TD]
[TD]Exp Streak %[/TD]
[TD="align: center"]24.00%[/TD]
[TD="align: center"]14.40%[/TD]
[TD="align: center"]8.64%[/TD]
[TD="align: center"]5.18%[/TD]
[TD]D6: =(D4^D5)*(1-D4)[/TD]
[/TR]
[TR]
[TD="align: center"]7[/TD]
[TD]Expected Tally[/TD]
[TD="align: center"]384.00[/TD]
[TD="align: center"]230.40[/TD]
[TD="align: center"]138.24[/TD]
[TD="align: center"]82.94[/TD]
[TD]D7: =D6*D3*(1-D4)[/TD]
[/TR]
[TR]
[TD="align: center"]8[/TD]
[TD]Actual Tally[/TD]
[TD="align: center"]390[/TD]
[TD="align: center"]227[/TD]
[TD="align: center"]141[/TD]
[TD="align: center"]81[/TD]
[TD]D8: 390[/TD]
[/TR]
[TR]
[TD="align: center"]9[/TD]
[TD]Error (Act-Exp)[/TD]
[TD="align: center"]6.00[/TD]
[TD="align: center"]-3.40[/TD]
[TD="align: center"]2.76[/TD]
[TD="align: center"]-1.94[/TD]
[TD]D9: =D8-D7[/TD]
[/TR]
[TR]
[TD="align: center"]10[/TD]
[TD]Error %[/TD]
[TD="align: center"]1.54%[/TD]
[TD="align: center"]-1.50%[/TD]
[TD="align: center"]1.96%[/TD]
[TD="align: center"]-2.40%[/TD]
[TD]D10: =D9/D8[/TD]
[/TR]
</tbody>[/TABLE]
Row 6 shows the expected probability for each streak length. Row 7 shows the expected tally for each streak length. Row 8 shows the actual tallies. Row 9 shows the difference in these percentages and Row 10 shows the percentage error.
My question is this: Are the values in Row 10 the best measures of how closely the actual tallies (Row 8) are to the expected tallies (Row 7)? If there is a better measure, I would appreciate some help understanding what it is and how to calculate it. I am looking for a measure that will allow me to rank the various tallies according to the error from the expected.
I hope I explained that adequately.
I am interested in comparing the "tally errors" is different "win streaks" in a random event, like a game, with a given probability of a win. The table shows results for win streaks of various lengths (Row 5). Columns D-G contain data for these 4 streak lengths over 4,000 games with an overall winning % (Wins/Games) of 60%.
Col H shows the formulas used for the calculations.
[TABLE="class: grid, width: 650"]
<tbody>[TR]
[TD="align: center"]R/C[/TD]
[TD="align: center"]C[/TD]
[TD="align: center"]D[/TD]
[TD="align: center"]E[/TD]
[TD="align: center"]F[/TD]
[TD="align: center"]G[/TD]
[TD="align: center"]H[/TD]
[/TR]
[TR]
[TD="align: center"]3[/TD]
[TD]#Games[/TD]
[TD="align: center"]4000[/TD]
[TD="align: center"]4000[/TD]
[TD="align: center"]4000[/TD]
[TD="align: center"]4000[/TD]
[TD]D3: 4000[/TD]
[/TR]
[TR]
[TD="align: center"]4[/TD]
[TD]Win %[/TD]
[TD="align: center"]60.00%[/TD]
[TD="align: center"]60.00%[/TD]
[TD="align: center"]60.00%[/TD]
[TD="align: center"]60.00%[/TD]
[TD]D4: 0.6[/TD]
[/TR]
[TR]
[TD="align: center"]5[/TD]
[TD]Streak Length[/TD]
[TD="align: center"]1[/TD]
[TD="align: center"]2[/TD]
[TD="align: center"]3[/TD]
[TD="align: center"]4[/TD]
[TD]D5: 1[/TD]
[/TR]
[TR]
[TD="align: center"]6[/TD]
[TD]Exp Streak %[/TD]
[TD="align: center"]24.00%[/TD]
[TD="align: center"]14.40%[/TD]
[TD="align: center"]8.64%[/TD]
[TD="align: center"]5.18%[/TD]
[TD]D6: =(D4^D5)*(1-D4)[/TD]
[/TR]
[TR]
[TD="align: center"]7[/TD]
[TD]Expected Tally[/TD]
[TD="align: center"]384.00[/TD]
[TD="align: center"]230.40[/TD]
[TD="align: center"]138.24[/TD]
[TD="align: center"]82.94[/TD]
[TD]D7: =D6*D3*(1-D4)[/TD]
[/TR]
[TR]
[TD="align: center"]8[/TD]
[TD]Actual Tally[/TD]
[TD="align: center"]390[/TD]
[TD="align: center"]227[/TD]
[TD="align: center"]141[/TD]
[TD="align: center"]81[/TD]
[TD]D8: 390[/TD]
[/TR]
[TR]
[TD="align: center"]9[/TD]
[TD]Error (Act-Exp)[/TD]
[TD="align: center"]6.00[/TD]
[TD="align: center"]-3.40[/TD]
[TD="align: center"]2.76[/TD]
[TD="align: center"]-1.94[/TD]
[TD]D9: =D8-D7[/TD]
[/TR]
[TR]
[TD="align: center"]10[/TD]
[TD]Error %[/TD]
[TD="align: center"]1.54%[/TD]
[TD="align: center"]-1.50%[/TD]
[TD="align: center"]1.96%[/TD]
[TD="align: center"]-2.40%[/TD]
[TD]D10: =D9/D8[/TD]
[/TR]
</tbody>[/TABLE]
Row 6 shows the expected probability for each streak length. Row 7 shows the expected tally for each streak length. Row 8 shows the actual tallies. Row 9 shows the difference in these percentages and Row 10 shows the percentage error.
My question is this: Are the values in Row 10 the best measures of how closely the actual tallies (Row 8) are to the expected tallies (Row 7)? If there is a better measure, I would appreciate some help understanding what it is and how to calculate it. I am looking for a measure that will allow me to rank the various tallies according to the error from the expected.
I hope I explained that adequately.