OZ Lotto Standard Deviation Distribution

  Number Frequency   Overdue Numbers   Odd/Even Numbers   High/Low Numbers   Sum and Root Sum   Hot and Cold Numbers   Most Common Pairs   Most Common Triplets   Most Common Quadruplets   Most Common Quintupletss   Mean, STDEV, and Range Trend   Mean Distribution   Range Distribution   STDDEV Distribtion   IQR Distribution   Clustering Distribution
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  Number Frequency   Overdue Numbers   Odd/Even Numbers   High/Low Numbers   Sum and Root Sum   Hot and Cold Numbers   Most Common Pairs   Most Common Triplets   Most Common Quadruplets   Most Common Quintupletss   Mean, STDEV, and Range Trend   Mean Distribution   Range Distribution   STDDEV Distribtion   IQR Distribution   Clustering Distribution

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

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Last 75 draws
From Jul. 2, 2024 To Dec. 2, 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 Jul. 2, 2024 to Dec. 2, 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 1-6 up to 43-47, 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 13-18 with 30 occurrences, suggesting a strong clustering in this interval. In contrast, the least frequent deviation interval is 1-6, 19-24, 25-30, 31-36, 37-42, 43-47 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 Australia's Oz Lotto

Oz Lotto, Australia’s first national lottery, has undergone several format changes since its launch in 1994. Below is the timeline of the Australia's Oz lotto format changes:

Period Format Supplementary Nos.
1994 - Oct. 11, 2005 6 numbers from a pool of 45 (6/45) 2 numbers from the same pool.
Oct. 18, 2005 - May 10, 2022 7 numbers from a pool of 45 (7/45) 2 number from the same pool.
May 17, 2022 - Present 7 numbers from a pool of 47 (7/47) 3 number from the same pool

Initially, the game required players to select six numbers from a pool of 45, and two supplementary numbers were drawn to help determine secondary prizes. In October 2005, the format was modified to increase the number of main numbers drawn from six to seven, still from a pool of 45, while retaining two supplementary numbers. This change made the jackpot more difficult to win but allowed for larger prize pools. In May 2022, Oz Lotto underwent another significant update. The number pool was increased from 45 to 47, while the game continued to draw seven main numbers. Additionally, the number of supplementary numbers increased from two to three. Along with this change, the minimum jackpot prize was raised from $2 million to $3 million, and the overall odds of winning any prize improved, creating more opportunities for players to win across additional prize divisions. These changes reflect Oz Lotto's ongoing efforts to remain engaging and competitive within Australia’s lottery landscape.

How Australia's Oz 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 6/45 format may have done so due to higher individual draw probability, but that same frequency can be misleading in the 7/45 or 7/47 formats. Furthermore, changes to the number pool also significantly affect how often a specific supplementary numbers appear.

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.

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