Listen carefully to your caddie. Grain has an effect on putting. All the grain goes towards the lowest point on the property, the 11th green. Your eyes will deceive you on some putts, particularly as it relates to speed and thus break, depending upon the direction of grain. The other thing to bear in mind is that many tees deliberately point in the wrong direction, often the worst offline angle. Be especially careful on the 3rd.
Consider the flow of the holes. The first is a short dogleg par 4 with 13 bunkers. The requirement for accuracy and distance control on all shots around Merion East begins right off the bat. After the short first are 5 long holes, the only 2 par 5s on the course are the 2nd and 4th in opposite directions, the first uphill (your line is always the tall white tree in the distance) and the last downhill (aim towards the distant tower with the fork on top and know that the second fairway beyond the large cross bunker shifts to the left. The 3rd, a slightly uphill par 3 looks like a Redan but the green slopes in the opposite direction and there is no possibility of running the ball onto the green. Also the green isn't offset like every other Redan concept replica. Try taking a few putts from around the massive green (48 yards long), particularly middle right to front left. It is one of the great greens in golf and very difficult to 2 putt. Take a look at the high back left shelf as it is pinned at times. The 5th is one of the great natural land-form holes in all of golf. The more you challenge the left side with the parallel creek and 2 bunkers, the flatter your lie and the far better angle into the canted green (right to left). In fact, look at the green while standing on the third and get a sense of the slope and when you're walking to your tee shot on 4, take a look at the slope of the green from that vantage point. The perspectives are quite different. The 6th runs in the same direction as the 5th but plays very differently with the large green with complicated interplays of slopes having a false front. You either have to fly the ball all the way above the false front or get it running early. Now comes the second act. Holes 7-13 are short holes requiring precise play. Playing close to the OB on 7 and 8 yield the best approach angle. On the 8th hole, play over the left edge of the right fairway bunker even if you can see the pin over the right side of the left fairway bunker. Make sure you're in the fairway because you'll need to have spin on the ball to hold the green. Have fun on this stretch and bear in mind, like those that know the course, the finishing 5 holes are the toughest in golf. It puts added pressure on many players to score well on the short stretch before the third and final act that is golf at Merion. Let us know your thoughts. By the way, keep an eye out for the championship tees. They add about 500 yards to the course and man are they challenging! The yardage added are on holes 2,3!!,5!!,6!!,12,14!(from back of practice green),15!,17! and 18!.