I'm wrapped we've got Roly signed up until 2020.
Roly has coached Freo for their last 4 seasons 2012-2015. Freo's ladder positions under Roly have been 7th, 3rd, 4th and 1st (2012-2015 respectively).
Since Freo's inception (1995), the only coaches to have a better consecutive four years are;
Alistair Clarkson (Hawthorn 2005-present) incl. 4yrs 2012-2015 with 1st, 1st, 2nd & 3rd (3 premierships).
John Longmire (Sydney 2011-present) 2012-15 with 3rd, 4th, 1st & 4th (1 premiership)
Chris Scott (Geelong 2011-present) 2011-14 with 2nd, 6th, 2nd & 3rd (1 premiership)
Mick Malthouse (Collingwood 2000-2011) 2008-11 with 8th, 4th, 1st & 1st (1 premiership)
Ross Lyon (St Kilda 2007-2011) 2008-11 with 4th, 1st, 3rd & 6th
Mark Thompson (Geelong 2000-2010) 2007-10 with 1st, 1st, 2nd & 2nd (1 premiership)
John Worsfold (West Coast Eagles 2002-2013) 2004-07 with 7th, 2nd, 1st & 3rd (1 premiership)
Leigh Matthews (Brisbane Lions 1999-2008) 2001-04 with 2nd, 2nd, 3rd & 2nd (3 premierships)
Mark Williams (Port Adelaide 1999-2010) 2001-04 with 3rd, 1st, 1st & 1st (1 premiership)
Kevin Sheedy (Essendon 1995-2007) 1999-2002 with 1st, 1st, 1st & 5th (1 premiership)
Denis Pagan (North Melbourne 1995-2002) 1996-99 with 2nd, 7th, 1st & 2nd (2 premierships)
The winning percentages for those coaches at those teams are;
Chris Scott (Geelong) 73.85%
Ross Lyon (@Freo) 71.59%
John Longmire (Sydney) 70.00%
Ross Lyon (@St Kilda) 64.55%
Denis Pagan (@North Melbourne) 62.50%
Alastair Clarkson (Hawthorn) 62.24%
Mark Thompson (@Geelong) 61.98%
Leigh Matthews (@Brisbane) 58.45%
Kevin Sheedy (@Essendon) 57.19%
Mick Malthouse (@Collingwood) 56.81%
Mark Williams (Port Adelaide) 56.03%
John Worsfold (@the Slime) 54.17%
From the stats shown, I think it's fair to say Roly is an Elite coach and hasn't exactly been the luckiest of coaches out there. That is, he is the only coach of our modern (Freo) era who has been so successful without winning a premiership ... YET!