Frankly, I've never been that satisfied with this presentation of my 52 Pages surprise system.
Just as a recap, this replaces the traditional "surprise roll" with a random determination of both parties' state of alertness, and then proceeds to play out the consequences logically. It assumes that monsters who surprise the party will have set up an ambush or approached them by stealth, giving the chance to detect such an approach; while if the party surprises the monsters, this means they have caught them out at a distracted moment, and the monsters have likewise failed to detect their approach.
The improvements below:
1. The party is now assumed to be alert or aware at all times when it matters during an adventure, eliminating one of the dice rolls and giving them a little more assumed agency over their actions. Keep in mind this is a rule set made for levels 1-3 and primarily dungeon adventures. The wilderness (Expert 52) rules will have more possibilities for the party to be distracted during a journey. Elsewhere in the rules I'll detail penalties for party members who don't rest. Of course, sleep is a need, too. Can we assume that a DM will figure out that a party member who is searching or otherwise engaged is "distracted"? Maybe not...
3. Going from an 8 sider to a 6 sider scale, the system is simpler with little loss of precision, and as a bonus you can roll up alertness more easily for large groups given the typical dice collection.