Lol @ Crazy ya sheet stirrer!!
You'll never be sure what your dog is, no particular breed is standing out. 23 " and 22 kg is only a small dog although he looks alot bigger in the pics.
Mate has one that looks similar but bigger and its got alot in it: kelpie, rottie, bluey, bully and shepherd
Is his tail missing or is he a bobtail? could have stumpy tail in him or similar. His legs have a solid look to them and he will fill out more when he matures, smaller breeds- staff,stumpy tail, or kelpie x's?? Has a bit 'boxerish' look to him slightly?