I recently played against Tau and had a first time experience of being on the receiving end of tau plasma rifle. Not fun. My opponent brought 6 crisis suits, all armed with plasma rifles, missile pods and multi-trackers. This is called the "Fireknife" configuration and although expensive, packs quite a punch against heavy infantry. The rest of his army was filled out with Kroot and 3 Broadsides. This did quite a number on my close assault Blood Angels army.
Playing against Tau is quite a challenge. With multiple mobile units, it's hard to get into grips with them. Also, by being protected by low-cost infantry, you are often caught out in the open after assaults and cut down by rapid firing plasma rifles. There is a solution however.
It's important to watch how an opponent reacts to your moves. A Tau general will try to move away from any fast-moving assault units as they approach, while laying down fire as they escape. Played well, this can force them to take chance and move out in the open.
So you set up a firebase with line of sight to where you force them to move, giving you a chance to shoot the crisis suits that often deny shots by hiding behind terrain. The fire base can also distract attention from you assault units by putting on the pressure while you units advance. You pose the opponent with a difficult choice; target the firebase or the assault units. Once you force a choice like that, you are on your way to winning.
Coming soon: Old Shatter Hands and his way of war.