Of the following 5 strategies for getting started assembling a jigsaw puzzle:

• Assembling the border and connecting other pieces to it
• Working your way out from one corner
• Trying to assemble faces or other recognizable parts of the picture
• Picking a random piece and working your way out from it
• Finding random pieces that fit together

which one or what combination results in the shortest solving time, on average, statistically speaking, according to the experts? Note that this is not a matter of experience. What do the studies on jigsaw-puzzle solving show?

Be sure to include the reasons why the strategy or combination of strategies is the fastest.