I've been concentrating on FICO 8, since it's the only one I can monitor in real time, or almost real time.
Bu it seems to me that the most likely score to be determinative of a mortgage rate is the FICO 5 EQ.
It is disturbing to me personally that this is the case, since my FICO 5 EQ is 73 points lower than my FICO 8 EQ.
There are no negatives in my EQ report.
Can someone point out some of the differences between 5 and 8, so I can begin figuring out how to appease this monster?
Anecdotally FICO 8 focuses on weights recent data more heavily when it comes to derogatories.
Tax lien added with an old lien already on report:
FICO 5: -5 points
FICO 8 -52 points.
Probably coincidental but they landed within 3 points of each other; by the six month mark my score had recovered on FICO 8. Similar behavior is seen with other types of derogatories; does not apply to clean files of course.
Also FICO 8 effectively mandates having both credit cards and installment loans open, and at pretty utilization metrics for both for optimal scoring. FICO 5 didn't particularly care: we saw that when we made the transition to FICO 8 on Scorewatch and 2 people each dropped from 680-690 to 636-640 from not having any open credit cards and just having installment history.
Also FICO 5 doesn't care about installment utilization, loan counts for credit mix and that's it.
Look in the reason codes for your particular differences TBH.
@JLK93 wrote:There are a number of differences between EQ FICO 5 (EQ04) and EQ FICO 8 (EQ08). Off the top of my head:
1. EQ FICO 5 has a maximum top score of 818 as opposed to 850 for EQ FICO 8.
2. EQ FICO 5 can be very sensitive to # of cards reporting balances for some scorecards. The $2 trick was developed specifically for this scoring model. EQ FICO 8 is much less sensitive.
3. EQ FICO 5 can experience large swings in sensitivity to # of cards reporting balances due to rebucketing. EQ FICO 8 is more stable.
4. EQ FICO 5 is generally more sensitive to utilization. This can probably vary according to Scorecard.
5. For both scoring models FICO only scores the first 6 inquiries.
That is all I can think of at the moment. Others can probably chime in with more differences.
Wow. Thank you very much!
@JLK93 wrote:
@JLK93 wrote:There are a number of differences between EQ FICO 5 (EQ04) and EQ FICO 8 (EQ08). Off the top of my head:
1. EQ FICO 5 has a maximum top score of 818 as opposed to 850 for EQ FICO 8.
2. EQ FICO 5 can be very sensitive to # of cards reporting balances for some scorecards. The $2 trick was developed specifically for this scoring model. EQ FICO 8 is much less sensitive.
3. EQ FICO 5 can experience large swings in sensitivity to # of cards reporting balances due to rebucketing. EQ FICO 8 is more stable.
4. EQ FICO 5 is generally more sensitive to utilization. This can probably vary according to Scorecard.
5. For both scoring models FICO only scores the first 6 inquiries.
That is all I can think of at the moment. Others can probably chime in with more differences.
Just remembered 2 more.
6. For EQ FICO 5, youngest account aging to 6 months is a major rebucketing event for some clean profiles. Youngest account aging to 1 year doesn't seem to hold any particular significance.
7. For EQ FICO 8, youngest account aging to 1 year is a major rebucketing event. Youngest account aging to 6 months is a yawn.
Thank you again 
You've provided me with a wealth of information
@Revelate wrote:Anecdotally FICO 8 focuses on weights recent data more heavily when it comes to derogatories.
Tax lien added with an old lien already on report:
FICO 5: -5 points
FICO 8 -52 points.
Probably coincidental but they landed within 3 points of each other; by the six month mark my score had recovered on FICO 8. Similar behavior is seen with other types of derogatories; does not apply to clean files of course.
Also FICO 8 effectively mandates having both credit cards and installment loans open, and at pretty utilization metrics for both for optimal scoring. FICO 5 didn't particularly care: we saw that when we made the transition to FICO 8 on Scorewatch and 2 people each dropped from 680-690 to 636-640 from not having any open credit cards and just having installment history.
Also FICO 5 doesn't care about installment utilization, loan counts for credit mix and that's it.
Look in the reason codes for your particular differences TBH.
Thank you so much Revelate. I'm writing all this down
@Revelate wrote:Anecdotally FICO 8 focuses on weights recent data more heavily when it comes to derogatories.
Tax lien added with an old lien already on report:
FICO 5: -5 points
FICO 8 -52 points.
Probably coincidental but they landed within 3 points of each other; by the six month mark my score had recovered on FICO 8. Similar behavior is seen with other types of derogatories; does not apply to clean files of course.
Also FICO 8 effectively mandates having both credit cards and installment loans open, and at pretty utilization metrics for both for optimal scoring. FICO 5 didn't particularly care: we saw that when we made the transition to FICO 8 on Scorewatch and 2 people each dropped from 680-690 to 636-640 from not having any open credit cards and just having installment history.
Also FICO 5 doesn't care about installment utilization, loan counts for credit mix and that's it.
Look in the reason codes for your particular differences TBH.
Followed your excellent advice to compare the negative reason codes!
The following reason codes appeared for FICO 5 which did not appear for FICO 8, thus giving me a clear path to improving the FICO 5 score:
new recent acct
recently looking for credit
too many cards carrying balance
Well that answers that, for my situation
Gotta remember that trick for future instances of wonderment at why a partcular score is lagging.