9/7 DB Quiz/Question!

[DOUBLE B]

Kd 6d 3h 5h 7h
Kd 6c 3h 5h 7h
Kd 6s 3h 5h 7h
Qd 6d 3h 5h 7h
Qd 6c 3h 5h 7h
Qd 6s 3h 5h 7h
Jd 6d 3h 5h 7h
For all the above the best play in 9/7 DB is 3h 5h 7h with EV of 2.2572
 
Jd 6s 3h 5h 7h
Jd 6c 3h 5h 7h
For the above two--best plays are Js & Jd respectively with EV of 2.2753.
Note not so for Jd 6d 3h 5h 7h with EV of 2.2429. 
 
Question: What sets Jd 6d 3h 5h 7h apart from Jd 6c 3h 5h 7h  & Jd 6s 3h 5h 7h.
 
Yes I know Jd & 6d are suited, but so are Kd 6d & Qd 6d.
 
The above is according to Bob D and his Win Poker.

[Lvkid7]

I'm assuming it's because of the straights(or straight flushes) possible. Holding only a K you can make two possible straights AKQJT or KQJT9. Holding only the Q you can make three straights AKQJT KQJT9 QJT98. Holding the J you can make 4 straights AKQJT KQJT9 QJT98 or JT987 and I'm guessing there's your difference.

[DOUBLE B]

I don't see how/why the 6d has any influence with your scenario.
The EV for Jd & 6d is 2.2429
The EV for Jd & 6c is 2.2753
The EV for Jd & 6s is 2.2753
Why the difference?

[onemoretry]

I don't see how/why the 6d has any influence with your scenario.
The EV for Jd & 6d is 2.2429
The EV for Jd & 6c is 2.2753
The EV for Jd & 6s is 2.2753
Why the difference?
 When you discard the six of diamonds, there is one less card available with which to make a flush in diamonds when you draw to the jack.