Has either of the OF gone through a season undefeated? What about only losing to their OF rivals?

I seem to recall that Rangers did it in the early days of the league but nothing more recently.

I would have thought it would have happened when you see the recent record in the EPL. Arsenal going undefeated, Chelsea only lost once in a season & even last season Arsenal & Chelsea only lost 3 & that wasn't good enough to win the league.

In 2001-02 Celtic only lost one game, to Aberdeen. They drew twice with Rangers as well as with Livingston and Hibs. A pretty remarkable season for them.

Rangers played 18, won 18 in the early 1900s/ late 1800s. Hearts finished second with 12 wins.

It's sad I know that

SPL Champions Number of Defeats (last ten)

2007/08 - Celtic (5)
2006/07 - Celtic (6)
2005/06 - Celtic (3)
2004/05 - Rangers (3)
2003/04 - Celtic (2)
2002/03 - Rangers (3)
2001/02 - Celtic (1)
2000/01 - Celtic (3)
1999/00 - Rangers (2)
1998/99 - Rangers (5)

Didn't Celtic only lose one game in the mid nineties under the late Tommy Burns and still lose out on the title?

95-96 I think

In the period that Celtic won nine in a row did Rangers not go undefeated until the last game of the season when they lost to Aberdeen?