Judging Thai fights is a much debated subject. It's a great way to score a battle between two fighters, but isn't incredibly easy to understand. So it isn't a surprise that other blogs and articles have tried to cover it.
Here are some reliable sources, from authority on TRADITIONAL MT judging Tony Myers, to help clear up your understanding.
What Techniques Score (Tony Myers)
*Must be a MT technique to score
*Can be any MT technique but must be visibly effective to score. The highest scoring is usually the technique that causes your opponent to end up on the floor
*Will not score if walked through, or countered with a equal or stronger technique
*Dominating the ring space can win you the round, and thus...
*Running away or tactics that show a lack of engagement in Muay Thai fashion (ex. grabbing ropes, falling on purpose when leg is caught) can cost you the round
How are the Fights Judged? (Tony Myers)
*Momentum counts: "although one boxer may begin strongly and dominate early in the fight, it's the finish that is important and a boxer behind early can be overtaken"
*Professional fights are judged as a whole and rounds don't have equal emphasis. Emphasis is given to a fighter finishing strongest over the last three rounds.
-R1 has the least significance and is often scored as a draw, and R2 may also be scored as such. Judges make note of the dominant boxer of these 2 rounds for reference.
-R3-5 are the most important, and in the case of a close fight the boxer who had the edge in the first two rounds will be awarded the win.
My Own 2 cents:
Often, we have people describing MT scoring to us by points. You'll hear that punches are worth 1, and kicks are worth 2...etc etc.
There is truth to that in the sense that kicks, elbows and knees are traditionally stronger and more damaging weapons than punches. So they generally score more favourably in Thailand. Punches can be just as devastating, but usually need a lot of visible effect for a Thai judge to score it as favourably as a body kick or knee.
So while MT judging follows no formal points system, this is why it is often explained as such and allows us westerners to conceptualize the scoring at a basic level.
Keep in mind, this isn't how fights are necessarily scored all over the world by every organization, including the amateur ones we compete in. This is traditional scoring for fights in Thailand, which many MT enthusiasts are trying to make standard over-seas.