Source: www.edmontonbridge.ca
On my convention card under 5 card majors , I have expected length ticked as 4 in 3rd or 4th seat . I do this because I like to preserve the sanctity of lead directors in 3rd seat or to be disciplined by opening my best suit . If that suit is a 4 card major so be it. I am from the Kiz school and I would never open 1
with xxxx in 3rd or 4th seat and 14 HCP’s with the hand that we were discussing . I would open a spade or cheat a point and bid 1NT .
When partner is a passed hand her “expected” HCP range from 0-12 . The average hand will be 6 points as a passed hand . This means that the opponents will buy the hand 50 % up to 75 % of the time. Why get partner off to a horrible lead ? In 1St and 2ND seat it is an automatic 1 opener and partner will allow for that with her opening leads . 3 rd & 4th are a different proposition because quite often you just open for a lead.
I loath “testimonials” as rationale to a bidding problem . Bridge logic should prevail . However for those into that : Peter Jones , Stan Cabay , Klimo , Bob Crosby are a few who would never open a diamond in 3rd seat with xxxx . Leads are way too important. Some people seem to have some hang up with 4 card majors.
For the first 50 years of Bridge , 4 card majors were the norm . In Toronto rubber Bridge and in England, 4 card majors are still the norm today . When partner is a passed hand , there is nothing wrong with opening 4 card majors if that’s where your values are . Peter Jones , myself , Stan Cabay have used that tactic successfully for as long as we played the game.
Closed minds are the biggest deterrent to learning and improving in any field …
Opening a diamond in 3rd seat with 
xx 
AKQx xxxx 
Axx is very very wrong. Opening 1 has advantages other then just “showing where you live” for lead purposes. Opening 4 card majors are surprisingly pre-emptive and force the opponents to pass or overcall at the 2 level. Quite often they do not have the requisite shape to enter the auction. There is also a tactical advantage to finding your major suit fit very quickly . Close major suit games are bid and made which are otherwise very difficult to find
Overcalling 4 card majors for a lead or the best out with a fix hand is quite often good strategy. Playing with BJ , I held AJ10x x AKx AQxxx and there was a diamond opener to my right. I overcalled 1
And BJ leapt to 4 . I passed and made +650. We opened up the slip and two pairs played the hand in 2 making 4 ! BJ’s hand Qxxxx Kxxxx x xx… so come up with a bid after a 2 overcall !!
Bridge is far more then following rote rules. Rules change depending on the vulnerability and whether you are in 3rd or 4th chair . Partner being a passed hand , necessitates a bidding system that takes that into consideration.