This comp makes use of the added 25 AD to all berserker units to deal immense splash damage to enemy teams. The comp revolves around running Olaf as your main carry and using Locket of the Iron Solari to buff up your berserker units which are all melee.
This comp has it's best start when you can find 3 berserkers and electric early. It's also quite important to get Locket early so you can win streak or find an early Olaf to put ideal items on Olaf instead. Last Whisper is also a good alternative to Infinity Edge as you can go without Desert with Last Whisper on Olaf.
The most ideal start would be to get 3 berserkers and electric going. This start can win streak very early especially if you make an early Locket on Jax. If you find Mundo early, you can place lockets on him, but since we sell Jax later, you can safely put it on Jax.
At level 6 you should prioritize putting in 6 berserkers and put electric back in at 7. If you have Berserker's Axe by now, you can run 6 berserkers with desert and drop Jax. At level 8, look for more Olafs, or complete your build with Karma or Qiyana.
Additional comp tips
Olaf will be your late game carry, so prioritizing items for him early can be a solid gameplan, but making early Locket's to winstreak can also result in a successful game even if you can't build perfect Olaf items.
Remember to position your berserkers in the back so that enemy teams are more clumped together.
Locket of the Iron Solari is a great item and Zeke's is a bonus item if you have extra items.
With Berserker's Axe on Kha'Zix, you are able to create another spot on your team while keeping Desert.
Running 2 Olafs is ideal, but if you cannot find a second Olaf 2, you can run Qiyana for assassin (if you have Youmuu's Ghostblade) or Karma to buff up Olaf.