The Standard Deviation is also very useful in analyzing how spread out the numbers tend to be from draw to draw. It also shows how consistently random the draws are over time

Related Lotto Standard Deviation Distribution

Last 75 draws
From May. 14, 2025 To Nov. 5, 2025

Histogram of Standard Deviation

The histogram of standard deviation measures how much variation or dispersion exists among numbers in each lotto draw. A low standard deviation means the numbers are close together, while a high standard deviation indicates they are spread out across the range. By dividing these values into bins, the histogram reveals whether draws tend to produce tightly grouped numbers or broadly spaced sets. This helps in understanding the randomness and variability of number distribution across many draws.

The chart below is a histogram of standard deviation of lotto combinations from May. 14, 2025 to Nov. 5, 2025 , covering 75 draws. The range of possible standard deviation is divided into categories or bins. In this case, the bins are defined as intervals such as 1-9 up to 64-69, each representing a continuous range of mean values.

This division is necessary because individual standard deviation values can vary widely, and grouping them into intervals makes patterns easier to observe. For example, by examining how frequently standard deviation fall into each bin, anyone can quickly see whether the draws are evenly distributed, clustered in particular ranges, or biased toward lower or higher values.

The histogram of standard deviations of lotto draws, showing how widely numbers vary within combinations reveals that the most frequent deviation interval is 10-18 with 35 occurrences, suggesting a strong clustering in this interval. In contrast, the least frequent deviation interval is 37-45, 46-54, 55-63, 64-69 with 0 occurrences, showing it is rarely observed. This indicates a noticeable concentration of draws around certain deviation intervals. Overall, the distribution shows clustering around specific deviation intervals, indicating that draws tend to gravitate toward these values.

Format Changes in US Powerball Lottery

Since its inception on April 22, 1992, the U.S. Powerball has undergone several significant changes in format and structure. At launch, Powerball became the first lottery game to use a dual-drum format—drawing five white balls from one set and one red Powerball from another—designed to create more prize tiers. Initially, players selected 5 numbers from 45 white balls and 1 from 45 Powerballs.

In November 1997, the format changed to 5/49 + 1/42. This was followed by another change in October 2002, expanding the white ball pool to 53 while keeping the Powerball at 42. By August 2005, the white balls increased again to 55. A major change occurred in January 2009, with the matrix becoming 5/59 + 1/39. Around this time, Florida joined the game, and the drawings were moved there.

One of the most notable changes came in January 2012 when the Powerball pool was reduced to 35, while the white balls remained at 59. Another significant format change was introduced in October 2015, adjusting the matrix to 5/69 + 1/26. This increased the odds of winning smaller prizes while making the jackpot harder to win, with overall odds shifting to approximately 1 in 292 million.

Period Format Powerball
April 1992 5 of 45 1 of 45
November 1997 5 of 49 1 of 42
October 2002 5 of 53 1 of 42
August 2005 5 of 55 1 of 42
January 2009 5 of 59 1 of 39
January 2012 5 of 59 1 of 35
October 2015 5 of 69 1 of 26

How US Powerball Lotto Format Changes Affect Your Number Strategy.

These format changes have a direct impact on statistical analysis. Mixing frequency data across different formats is not advisable because each version of the game has a different number pool and probability structure.

For example, a number that appeared frequently in the 5/49 format may have done so due to higher individual draw probability, but that same frequency can be misleading in the 5/69 formats.

Therefore, for meaningful analysis, it’s essential to treat each format as its own distinct dataset. Analyzing trends or frequencies should be restricted to results from within the same format period, especially if the goal is to inform number selection in the current game structure.