Issues with Random Number Generation Methods

So, I saw this giveaway thread and had some thoughts on how to make the random number generation process better. Is this method solid or am I missing something key?

Honestly, the entropy is super low with just the last two digits. Only 100 possible outcomes? That makes it way too easy for people to guess the results, especially in bigger contests.

Here’s a more secure way to do it: 1. The server picks a random entropy and keeps it to itself. 2. It then releases a hash of that entropy to ensure it can’t change things later (SHA256 is good, since we’ll use SHA512 later). 3. Announce one or more future block heights as extra entropy. 4. Lock in the participant list with each one getting a unique index. 5. Publish the algorithm that shows how results will be derived.

Thanks for breaking it down like that! As a total noob, I get how more entropy means better randomness. Just wanted to say I appreciate the clear explanation. Locking this now, got what I needed.