Sorry, VHG, your 'odds and evens' theory doesn't hold water.
Every combination of 6 numbers has a (roughly) 1 in 14 million chance of winning the jackpot, irrespective of how that combination is selected. You could choose 1, 2, 3, 4, 5 & 6 or you could select exactly the same 6 numbers which won the most recent jackpot. It makes no difference.
However, while you can't improve your chances of winning the jackpot, you can improve your chances of a decent payout if you win. For example, I read somewhere that several hundred people choose 1, 2, 3, 4, 5 & 6 as their regular selection of numbers. If you join them, your chances of winning are neither lessened nor improved but, if those numbers are drawn out, you'll have to share the jackpot with hundreds of others.
Similarly, many people select their numbers based upon family birthdays. Since their are no more than 31 days in a month, that means that large numbers of participants only select numbers between 1 and 31. So, if you choose 2, 5, 7, 18, 19 & 28 you might be sharing your jackpot payout with one or more people who base their numbers upon birthdays. Whereas choosing 32, 35, 36, 37, 46 & 47 guarantees that, if you win the jackpot, you won't have to share with anyone who bases their selection upon birthdays.
Chris (a maths graduate who vaguely remembers at least a little about statistics!)