(I have just read the entirety of the rules section again for this book, and would love to try it out - but that is a discussion for another time and place ;)).
SIF RPG is a fully Skills-Based System. You have a concept in mind and build it through choice.
I am loving the elegance of the system and would love to try it out. Here, Ability Scores/Attributes and Skills are not treated separately. Instead, you simply have Abilities!
Abilities are a combination of what we would think of as Skills and Ability Scores/Attributes. They cover all the important things a character might do in a fantasy setting (minus Magic).
The Abilities are: Agility, Animal Handling, Athletics, Awareness, Cunning, Deception, Endurance, Fighting, Healing, Knowledge, Language, Marksmanship, Persuasion, Status, Stealth, Survival, Thievery, Warfare and Will. That is it.
All PCs start with 2d6 in each of these. You can raise them of course (and you can even take one down to 1d6 indicating a real weakness in that area). Whenever you check one of these, you simply roll the amount of dice you have in that ability.
Now, these are quite broad areas, so where do specialty skills fit in. Well, each Ability has Specialty areas. Specialties add Bonus Dice to the roll. (Bonus dice replace dice in the check, they don't add; I will give an eg. below).
So, Fighting Specialties inc. all the different weapons types (eg: Axes), whereas Persuasion has the Specialties: Bargain, Charm, Convince, Incite, Intimidate, Seduce and Taunt. Animal Handling has the following Specialties: Charm, Drive, Ride, Train.
How does this work. (Well, wonderfully in my mind). So the GM asks for an Animal Handling check and allows bonus dice for Riding when a player is asked for a check whilst riding. Basically everyone can make the base roll and others who are better roll Specialty Bonus dice. So a player with Animal Handling 2 and and Ride 2B, rolls 4 dice but takes the best 2. (Thus specialties don't mean you make rolls of extraordinarily high values, but they ensure consistently high-range values (still with the chance of failure though).
So, in a way it is a combination of where DnDN is heading (with Ability checks and bonuses for specialties) and Savage Worlds (being skills-based and including areas like Fighting and Marksmanship). But it has the elegance of not having two areas to look at (Ability scores/Attributes vs Skills) AND makes it very clear what you are rolling.
Certainly a system that sounds very good to me and one I definitely want to try. Like the old d6 System West End Games used for the Star Wars, but a lot more refined. Its design is fantastic (and written by Robert J. Schwalb - a long time DnD writer (and I believe the one who actually lectures on game design). The system seems to be called the Chronicle System, so maybe it is one other Green Ronin products may use)?