Why balanced odd/even and high/low splits turn up most often

LottoBase Team · 12 October 2026 · 5 min read

Sort a list of past Lotto results by how many of each draw’s six main numbers were odd and a pattern shows up quickly. Three odd and three even is everywhere, four and two is close behind, and an all-odd or all-even draw is a rarity. The same happens with low and high numbers. This post explains why, using some coin tosses and a bit of counting, and then covers what the odd/even and high/low splits in LottoBase are showing you.

Start with four coin tosses

Toss a coin four times and write down each result in order: heads, tails, tails, heads, and so on. There are 16 possible sequences, from four heads in a row to four tails in a row, and with a fair coin every one of those 16 sequences is equally likely. That just means none of them is favoured over any other. Heads-heads-heads-heads is exactly as likely as heads-tails-tails-heads.

Now count only how many heads came up. Four heads can happen one way, and so can four tails. But two of each can happen six ways: HHTT, HTHT, HTTH, THHT, THTH and TTHH. None of those six is likelier than all heads; there are simply six of them, so over many sets of four tosses you will see a two-and-two split about six times as often as four heads.

That is the whole idea: balanced results are common because there are many more ways of producing them, not because the coin prefers balance.

The same counting with 59 Lotto balls

Lotto draws six main numbers from 1 to 59. Of those 59 numbers, 30 are odd and 29 are even. A “combination” here just means a set of six numbers where the order does not matter: 4, 17, 22, 31, 40, 58 is the same line however the balls drop. There are 45,057,474 combinations in Lotto, each exactly as likely as any other, which is where the odds of 1 in 45,057,474 come from. Sort them all by how many odd numbers they contain and you get this:

Roughly one line in three is an exact three-and-three split. Add the four-and-two and two-and-four rows and you have about four lines in every five. The all-odd and all-even lines together come to less than 2.5%: there are around 31 three-and-three lines for every all-even one. And because there is one more odd number than even, the odd-heavy rows are slightly bigger than their even-heavy mirror images.

Because every line is equally likely, the share of lines in each group is also the share of draws you would expect to land in that group over a long run. Nothing is steering the machine towards balance; balanced lines just make up most of the field.

High and low work the same way

For the high/low split, draw a line through the middle of the 59 numbers. One side ends up with 30 numbers and the other with 29, exactly as with odd and even, so the counting comes out identically: the same seven rows, with the 30-number side taking the place of odd. Six low numbers, or six high ones, is just as rare as an all-odd draw, for the same reason.

What it does and doesn’t mean

This is where it is easy to take the wrong lesson. A balanced split is common among winning lines because it is common among all lines; it says nothing about any particular line. Your three-and-three line has exactly the same chance as an all-odd line: 1 in 45,057,474 each. Choosing a balanced line simply puts you in the biggest crowd.

If that sounds familiar, it is the same reason a winning line’s total usually lands near the middle of its range, which we covered in why a winning Lotto line usually adds up to around 180.

Where to see your own split in LottoBase

On the Numbers tab, whose on-screen title is “Your Numbers”, switch from the Results view to the Insights view. Alongside the sum of your selected numbers against the average winning sum, you will find the odd/even split and the high/low split for the line in front of you. Change a number, using Random Pick or by tapping a ball to open the Number Picker, and the splits update with it.

What you do with that is up to you. Some players like their lines to look like a typical draw; others keep one lopsided line on a ticket because they like the look of it. When a ticket carries several lines, the splits show at a glance whether they are all built the same way. Once you are happy with a set, Add to Ticket saves it.

So which would you rather play: a line that looks like most past draws, or one of the rarer lopsided ones that is every bit as likely to come up? Either is a perfectly sound choice. The lottery is a game of chance, so it is worth playing with only what you can comfortably afford.