125fcr > 5%
Come again
Here's why you are completely wrong, like always :
I repeat, this build is dedicated to play on p1 or p3, running high density areas.
You take the wp to the current TZ and you start farming right away.
This is not a build suited to hunt bosses or do some rushes.
You are constantly doing the same :
amp - telestomp - CE - next
125% fcr means you gain 1 frame between amp and telestomp.
You cannot cast CE right away, your merc needs the kill first.
You gain another frame between CE and the next tele.
Amp's radius is so big that you basically cast it only once per 2 packs.
We're now at 2.5 frames gained per 2 packs, compared to a 75fcr build.
Let's assume we kill on average 30 packs per TZ runs...
that's 2.5 * 15 = 37.5
and let's add some extra 30 tele per run (30 * 1 frame) for general mouvement.
You just saved 67.5 frames
That's 2.7 seconds
Now what did we lose on the other hand by not using FF?
Andy is by very far the best helm for your merc (guillaume's would be an option if you tried to make this build work on p8, but that's a very stupid idea)
Without a fire res jewel, he will die from time to time, and you can't run without him like other builds.
That's already way more than 2.7s lost per run.
So you use a 15ias/30fire jewel instead of a 15ias/40ed
That's a 3.5% dps loss, directly translated in 3.5% slower kill speed per pack (you know? That delay where you have to wait for the merc kill before casting CE?)
That's also more time required to summon your army each new game.
Right here you already lost way more than 2.7s AGAIN
But that's not all
That 5% fire pen loss also happens to greatly improve the odds of your CE to fail at 1-hit killing stuff.
Yup
The maximized build achieves a threshold where you're just very slightly doing above 100% of the mobs hp with 1 CE.
Lose only 5% fire pen and suddenly its very frequent that your CE was sadly lacking that final little bit of dmg required to kill.
You end up casting CE way more often.
Each extra CE needed is 9 more frames lost.
That alone is also way more time lost per game than that 2.7s
But wait! That's not over!
You also lost your resist fire aura
Anyone who played a summoner knows how fire dmg is the only thing that kills your skellies and IG.
They get instantly bursted by stuff like venom lords' inferno or diablo's spells
We're not talking about seconds here, but minutes lost.
Your run is basically over whenever this happens... and it happens quite often without FF.
Come again
noob