So, I've been playing around with sticking to different succession types, and now I've been trying out prolonged seniority. True, it has lots of disadvantages, such as being almost always with short reign penalty instead of long reign bonus, and being stuck more often with drooling incapable bed-ridden wreck of a man, but there is a number of advantages. The obvious is, it allows for an easy unification of lands ruled by your wide-spread dynasty. But you still have to work beforehand to propagate your kinsmen all over the map at first. Also it protects lands from going outside of your dynasty due to being inherited by someone married matrilineally (or by female married normally), but elective helps here better.
However, there are two pretty major advantage, that add up over long periods of seniority. First, your dynasty prestige rockets, as it counts number of different occasions of titles held, so ten geezers holding crown for a year each grant ten times as much prestige points for the dynasty as one average guy ruling for ten years (and often people tend to put some young boy for many decades of rule). As your dynasty prestige rises, your kinsman all get greater starting bonus to prestige(from birth), and tend to marry people of higher descent (not wishing to marry minors due to "prestige effects"). That is already pretty great an advantage, especially if your dynasty is big and mostly outside of your direct control.
Second advantage is perhaps debatable, as it affects only the final score, but still, it allows for some ridiculous numbers in it as well. As prestige and piety are added to your score after the death of your current character, but can accumulate pretty much before you start playing as him, switching through ten dukes or kings, that lived eventful lifes before being controlled by you for couple years, adds maybe not ten times as much as you could achieve over the lifetime of dedicated control over one ruler from childhood to seniority, but still, few times more. Add to that effect of increased "base" prestige from births (and intradynastic marriages), that at some point reaches into thousands with seniority, and you are ensured to beat score of anyone that doesn't use it.
That is, if you manage to survive and keep your realm from ever-persistent threat of falling apart. But, well, it's too boring to have a stable realm of electives or primogenitures anyway.
However, there are two pretty major advantage, that add up over long periods of seniority. First, your dynasty prestige rockets, as it counts number of different occasions of titles held, so ten geezers holding crown for a year each grant ten times as much prestige points for the dynasty as one average guy ruling for ten years (and often people tend to put some young boy for many decades of rule). As your dynasty prestige rises, your kinsman all get greater starting bonus to prestige(from birth), and tend to marry people of higher descent (not wishing to marry minors due to "prestige effects"). That is already pretty great an advantage, especially if your dynasty is big and mostly outside of your direct control.
Second advantage is perhaps debatable, as it affects only the final score, but still, it allows for some ridiculous numbers in it as well. As prestige and piety are added to your score after the death of your current character, but can accumulate pretty much before you start playing as him, switching through ten dukes or kings, that lived eventful lifes before being controlled by you for couple years, adds maybe not ten times as much as you could achieve over the lifetime of dedicated control over one ruler from childhood to seniority, but still, few times more. Add to that effect of increased "base" prestige from births (and intradynastic marriages), that at some point reaches into thousands with seniority, and you are ensured to beat score of anyone that doesn't use it.
That is, if you manage to survive and keep your realm from ever-persistent threat of falling apart. But, well, it's too boring to have a stable realm of electives or primogenitures anyway.
