Svenskt Respitsystem (SRS), formerly known as Leading Yard Stick and

Lidingö Lidingö, also known in its definite form ''Lidingön'' and as ''Lidingölandet'', is an island in the inner Stockholm archipelago, northeast of Stockholm, Sweden. In 2010, the population of the Lidingö urban area on the island was 31,561. It is ...

Yard Stick (LYS). SRS is a semi-empirically based

handicapping Handicapping, in sport and games, is the practice of assigning advantage through scoring compensation or other advantage given to different contestants to equalize the chances of winning. The word also applies to the various methods by which th ...

system used in yacht racing in the

Nordic countries The Nordic countries (also known as the Nordics or ''Norden''; literal translation, lit. 'the North') are a geographical and cultural region in Northern Europe and the Atlantic Ocean, North Atlantic. It includes the sovereign states of Denmar ...

. The first version of the handicap system was developed in 1970 by the Swedish

yacht design Shipbuilding is the construction of ships and other floating vessels. It normally takes place in a specialized facility known as a shipyard. Shipbuilders, also called shipwrights, follow a specialized occupation that traces its roots to befor ...

er Lars-Olof Norlin. He based the system on regatta results from the

Round Lidingö Race Round Lidingö Race ( sv, Lidingö runt), is a one course sailboat race, counter clockwise round Lidingö Municipality in the inner part of Stockholm archipelago arranged by Lidingö Segelsällskap, and is held annually the second Saturday in May, ...

. His own design,

Allegro 27 Allegro may refer to: Common meanings * Allegro (music), a tempo marking indicate to play fast, quickly and bright * Allegro (ballet), brisk and lively movement Artistic works * L'Allegro (1645), a poem by John Milton * ''Allegro'' (Satie), an ...

, was used as the benchmark and was by definition assigned a LYS value of 1.00. Every yacht model has a SRS number that was previously based on results in regattas or, for new models, based on a

velocity prediction program A velocity prediction program (VPP) is a computer program which solves for the performance of a sailing yacht in various wind conditions by balancing hull and sail forces. VPPs are used by yacht designers, boat builders, model testers, sailors ...

(VPP) as in

IMS Ims is a Norwegian surname. Notable people with the surname include: * Gry Tofte Ims (born 1986), Norwegian footballer * Rolf Anker Ims (born 1958), Norwegian ecologist See also * IMS (disambiguation) Ims is a Norwegian surname. Notable people wit ...

and some other handicapping systems. The SRS number is multiplied by the measured time in order to get the handicap corrected time. Thus, a yacht with SRS 1.30 needs to sail at least 30% faster than a yacht with SRS 1.00 to win over it.

Trimaran A trimaran (or double-outrigger) is a multihull boat that comprises a main hull and two smaller outrigger hulls (or "floats") which are attached to the main hull with lateral beams. Most modern trimarans are sailing yachts designed for recreati ...

s of the type open OMRA 60, designed for racing only, have SRS values above 3.0. The system was revised in 2011 and onwards, and is now primarily based on a secret calculation formula that should reflect the performance of each yacht. The formula is secret to prevent development of designs that are optimised for SRS racing. As the system is semi-empirically based the SRS number for each individual model might be subject for evaluation and eventually change. This particularly applies to new models based on VPP. The system enables yachts of all sizes and types to compete with each other. SRS 1.00 would equal an average boatspeed of 5.5

knot A knot is an intentional complication in cordage which may be practical or decorative, or both. Practical knots are classified by function, including hitches, bends, loop knots, and splices: a ''hitch'' fastens a rope to another object; a ' ...

s on a circular course at a wind speed of 5.0 m/s.

SRS numbers

The numbers are agreed on by an internordic group. The group is responsible for maintaining a standard list, and agree on SRS values for models that are not yet on the list. If there are sufficient numbers of a specific model, the model will become a standard model. The standard list is under constant review and change, and an updated list can be found a
norlys.org

References

{{Yacht handicapping rules Handicap (sailing) Sailing in Sweden 1970 in sailing