There are a few things I do consider "locks"

This is mainly in a team sport like rugby where one country can be unbelievably dominating over another. A great example is NZ vs USA. USA will NEVER win (not unless they develop a pro league). There's just so much skill involved in the game, and a few injuries to key kiwis still wouldn't be enough for USA to have a shot.

Windies vs aus, well it's not a lock, but looks fine at 1.24.

"Hardly worth watching at moment , which is a shame"

Totally agree.

I don't usually agree there are "locks". Eg someone will say the tigers over the bunnies or something. But even in the NRL any dog can win on it's day. You want to look for highly professional teams vs amateur teams. Rugby is a GREAT sport for this. It's whether the bookies will offer enough of a price to make it worth betting (if it's 1.01 what's the point??). You would need to get a large chunk of your BR down to make the growth worthwhile, but then you run into betting limits.

Again, most pro leagues are bad to do this (nrl, afl, nfl etc), but sports where professional teams play amateur teams are great (rugby).