Post by FriedrichPsitalon on May 15, 2004 8:29:19 GMT -5
At the request of some of our newer members (and by the need of some of our older ones) I thought I'd put together a brief treatise on the usefulness of sentinel nets, and how you can best set them up to protect more cities with less units. Mastering the art of sentinel nets allows you to protect more with less (because you can concentrate your defenses,) gives you less gray hairs (don't have to check every 15 seconds,) and makes you better looking to members of the opposite sex. No- really!
Okay, first example - this is a somewhat typical empire. We're going to come back to it at the very end, but for now, mentally decide where YOU would put "watchers" if this was your empire.
Now, the art of sentinel nets focuses on two ideas - that you want to know when someone is coming to attack you, and that you know with enough time to respond aggressively. Typically, I find that needed response times - with good road networks - average between 2 and 3 turns. So, we want our sentinel nets to give us about that much warning.
Here's an example of a "no net/lousy net" situation:
This player is, in effect, waiting to die if this is an elimination game. The red arrows indicate lines of extreme danger - routes that have almost no warning (or no warning!) before the city is under direct threat. While the southern routes are covered, the southeast is moderate (lousy terrain).... but the eastern route, and particularly the eastern naval route, are extremely likely to attract attention. A galley attack could land units RIGHT BESIDE the city without even using a double move!
Some players would allow this to pass, however, simply because there are no "easy" sentinel points in the east - no mountains, etc. Notice how with three units you can completely sew up that area, however, as indicated by the blue dots. (In truth, even with the blue dots, an extremely small eastern attack line does exist - see if you can spot it - that would only give 1 turn's warning, but it is still a vast improvement over "Hi! We're here to take the city now!")
In this next example, you have someone making a half-hearted attempt at a sentinel net, but the lack of real interest in the task will get them killed as well.
This player's sentinel net is would probably keep them alive against newer players. It does cover MOST of the main line of approach, and one of the coastal routes. A veteran player, though, would quickly sniff out that horrible, terrible, game-ending red line in the center and make the defender pay for it. Also, this city (though it appears to not have this worry at all) is very ripe for naval attack, as indicated by the second red arrow. Just because you don't have a coastal city, doesn't mean galleys can't kill you.
In this case, placing a sentinel anywhere in the path of the land-red arrow would give the needed warning, and the seaward route has two options: the snow-capped mountain in the peninsula, or even a sentinel on the mountain in southeast Tenochitlan's borders! (Hint: More warning is better, so the mountain is a better choice.)
Now let's take a look at something I call "the determined new guy." Here's a player who very much WANTS to use sentinel nets properly and has the right number of units in play, just not quite perfectly placed....
This is a good sentinel net. It watches out in front of the player with enough warning to react fairly well (assuming there's a bit more of an empire behind Tlatelolco, obviously.) It watches for anything coming by sea to the east, and projects in all directions on land. Against most players, this sentinel net would suffice - and indeed, many players get "This good" at sentinel nets and never better, simply because this one works often enough that they just say "Wow, nice trick" when it gets beaten. The two main threats here are the seaward route to the west (fairly obvious approach and strike) and the yellow-red lines I've drawn. Because there are extra mountains in the way, those two spears are limited in what they can see. If an opponent knew they were there, they could easily scoot up on the neighboring mountain and kill them with a fast double move - allowing you to know SOMETHING was coming, but not what - which is a recipe for getting drawn out in the wrong direction and slaughtered. Fixing this one is very easy - have the western spear move south, and the eastern spear move southeast, and put something on the desert coast to catch the last threat.
Now let's take another look at our first example, the "Full grown" civilization.
Okay, first example - this is a somewhat typical empire. We're going to come back to it at the very end, but for now, mentally decide where YOU would put "watchers" if this was your empire.
Now, the art of sentinel nets focuses on two ideas - that you want to know when someone is coming to attack you, and that you know with enough time to respond aggressively. Typically, I find that needed response times - with good road networks - average between 2 and 3 turns. So, we want our sentinel nets to give us about that much warning.
Here's an example of a "no net/lousy net" situation:
This player is, in effect, waiting to die if this is an elimination game. The red arrows indicate lines of extreme danger - routes that have almost no warning (or no warning!) before the city is under direct threat. While the southern routes are covered, the southeast is moderate (lousy terrain).... but the eastern route, and particularly the eastern naval route, are extremely likely to attract attention. A galley attack could land units RIGHT BESIDE the city without even using a double move!
Some players would allow this to pass, however, simply because there are no "easy" sentinel points in the east - no mountains, etc. Notice how with three units you can completely sew up that area, however, as indicated by the blue dots. (In truth, even with the blue dots, an extremely small eastern attack line does exist - see if you can spot it - that would only give 1 turn's warning, but it is still a vast improvement over "Hi! We're here to take the city now!")
In this next example, you have someone making a half-hearted attempt at a sentinel net, but the lack of real interest in the task will get them killed as well.
This player's sentinel net is would probably keep them alive against newer players. It does cover MOST of the main line of approach, and one of the coastal routes. A veteran player, though, would quickly sniff out that horrible, terrible, game-ending red line in the center and make the defender pay for it. Also, this city (though it appears to not have this worry at all) is very ripe for naval attack, as indicated by the second red arrow. Just because you don't have a coastal city, doesn't mean galleys can't kill you.
In this case, placing a sentinel anywhere in the path of the land-red arrow would give the needed warning, and the seaward route has two options: the snow-capped mountain in the peninsula, or even a sentinel on the mountain in southeast Tenochitlan's borders! (Hint: More warning is better, so the mountain is a better choice.)
Now let's take a look at something I call "the determined new guy." Here's a player who very much WANTS to use sentinel nets properly and has the right number of units in play, just not quite perfectly placed....
This is a good sentinel net. It watches out in front of the player with enough warning to react fairly well (assuming there's a bit more of an empire behind Tlatelolco, obviously.) It watches for anything coming by sea to the east, and projects in all directions on land. Against most players, this sentinel net would suffice - and indeed, many players get "This good" at sentinel nets and never better, simply because this one works often enough that they just say "Wow, nice trick" when it gets beaten. The two main threats here are the seaward route to the west (fairly obvious approach and strike) and the yellow-red lines I've drawn. Because there are extra mountains in the way, those two spears are limited in what they can see. If an opponent knew they were there, they could easily scoot up on the neighboring mountain and kill them with a fast double move - allowing you to know SOMETHING was coming, but not what - which is a recipe for getting drawn out in the wrong direction and slaughtered. Fixing this one is very easy - have the western spear move south, and the eastern spear move southeast, and put something on the desert coast to catch the last threat.
Now let's take another look at our first example, the "Full grown" civilization.
