Historically there is precedent for a distance only penalty or a stroke only penalty. Certainly the stroke and distance for OOB doesn't appear to have been cast in stone. Following is a brief summary of the history from
http://www.ruleshistory.com/lost.html_________________________________________________________________________________
Out of Bounds
The term out of bounds was first defined in 1899 as being outside the recognised boundaries of the course. Penalty distance only.
1908 Redefined as all ground on which play is prohibited. Penalty distance only still, but may be changed to stroke and distance by local rule for both forms of play. Also, a ball out of bounds may be treated as lost by local rule, (i.e. lost hole in match play). This change was not adopted by the USGA until 1915, although the local rule adjustment was not incorporated.
1920 Stroke and distance, but now the penalty stroke may be remitted by local rule.
1947 USGA and 1950 R&A. Distance only, and no provision for change by a local rule.
1952 Stroke and distance.
1960 USGA experimentally changed to distance only.
1961 USGA back to stroke and distance. in addition, the USGA allowed an alternative procedure of stroke only - dropping a ball within two club lengths of where the ball went out of bounds on courses where the penalty of stroke and distance would be "unduly severe".
1964 USGA allowed a local rule to be adopted which allowed a stroke-only option if it was felt that stroke and distance would be "'unduly severe."
The player could drop a ball within two club-lengths of where the original ball crossed the out of bounds line. Reasonable evidence was required both that the ball had gone out of bounds and as to the point of crossing. In the absence of either, stroke and distance was the only option.
Rescinded in 1968.
From the introduction of out of bounds, a ball was out of bounds when the greater part of it lay out of bounds. From 1950, all the ball has to be out.
When out of bounds is defined by a line, the line was in bounds until 1954.
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